A natural classification of the Hydroidea has yet to be put forward.
Within this classification of uniforms, there are several distinctions.
A statement may now be given of Gadow's classification of birds, in which the extinct forms have been intercalated so far as possible.
Their shape and size varies greatly and is often of use in classification.
For the development of this classification see Element.
This is the great difficulty of classification.
Haeckel's classification of 1866 was only a first attempt.
The classification of snakes has undergone many vicissitudes.
The terms employed, especially for the subdivisions, cannot be easily translated into other languages, and the English equivalents in the following table are only put forward tentatively Richthofen'S Classification Of Mountains I.
This will perhaps be the most convenient place to mention another kind of classification of birds, which, based on a principle wholly different from those that have just been explained, requires a few words, though it has not been productive, parte.
Blanchard published some Recherches sur les caracteres osteo- logiques des oiseaux appliquees a la classification naturelle de ces animaux, strongly urging the superiority of such characters over those drawn from the bill or feet, which, he remarks, though they may have sometimes given correct notions, have mostly led to mistakes, and, if observations of habits and food have sometimes afforded happy results, they have often been deceptive; so that, should more be wanted than to draw up a mere inventory of creation or trace the distinctive outline of each species, zoology without anatomy would remain a barren study.
Its basis is the classification of Cuvier, the modifications of which by Des Murs will seldom commend themselves to systematists whose opinion is generally deemed worth having.
Few, if any, of the faults of that classification are removed, and the improvements suggested, if not established by his successors, those especially of other countries than France, are ignored, or, as is the case with some of those of L'Herminier, are only cited to be set aside.
Meanwhile the English naturalist, John Ray, was studying the classification of animals; he published, in 1705, his Methodus insectorum, in which the nature of the metamorphosis received due weight.
Westwood (Modern Classification of Insects, 1839-1840) connects these older writers with their successors of to-day.
The situation of the lateral nervestems in the different genera with respect to the muscular layers lends definite support to the interpretation of their homologies here given and forms the basis of Burger's classification.
In the second classification (2) is typical of the " cold " process, whilst (I), (3), (4) are effected by the, boiling " process.
His contributions on the Mesozoic reptiles of Great Britain culminated in his complete rearrangement and classification of this group, one of his greatest services to palaeontology.
The like must be said even of the contribution to the problem made by August Pott,' though he has helped to define one condition of success - the classification of the strata in " Western " texts - and has taken some steps in the right direction, in connexion with the complex phenomena of one witness, the Harklean Syriac.
This classification is founded on the kinds of problems arising from the combinations.
In polymorphism, the taxonomic classification of species does not always match up with a tight genetic definition.
A controlled virus taxonomical and functional classification has been used for all the proteins and protein families in the database.
Colors in brackets, " [] ", are assumed from the spectral classification.
Grading criteria attached to each honors degree classification are appended.
My degree classification may be affected by my choice of options.
We also present the results of the phoneme classification experiments conducted on the TIMIT corpus of continuous speech.
The framework can be easily used for quantitative comparison of texture classification algorithms.
Species and habitat classification provides a language through which data can be communicated at a national and international level.
The code need only be observed if the additional material will raise the classification category of the work beyond previously classified versions.
These use a range of different parameters for classification, so that they are not strictly comparable.
Surgery in patients with liver dysfunction The Child-Pugh classification is a useful method of staging the progress of liver decompensation.
Others are less complimentary of the benefits of classification using dentition.
The use of standard classification schemes will improve resource discovery [40] .
Classification kept as a machine-gun emplacement, June 7 1941.
Bacterial exotoxins [IRP] Classification of bacterial exotoxins based on their mode of action at the cellular level.
Classification of fluorescent soft rot Pseudomonas bacteria, including P. marginalis strains, using whole cell fatty acid analysis.
Muybridge (1899) is the oldest known source on the classification of quadrupedal gaits in general, including elephant gaits.
Owners of vacant property may wish to avoid liability by bringing their hereditament under the classification of ' relevant industrial hereditament ' .
The HOST classification makes use of the fact that the physical properties of soils have a major influence on catchment hydrology.
It is the third criterion that is often called into question by Shaffer's classification of stochasticity primarily because of formalization indeterminacy.
Cross- classification of these inflection markers encodes natural classes of inflection markers encodes natural classes of inflection.
Advantages of using classification schemes include improved subject browsing facilities, potential multi-lingual access and improved interoperability with other services.
Before the classification procedure, cloud -cover reduced composites of the Canadian landmass, each spanning 10 day periods are created.
Now we can examine a situation illustrating the pitfalls of classification tree.
Chapter 1 also offers a classification of semantic types of situational plurality.
He was immensely proud of his " A " classification accorded by the " New Domesday scribe " .
The requirements in relation to the classification of long-term liabilities should be made more rigorous.
Under the ' Analysis ' menu, choose ' Classification ' which allows you to classify the entries contained within a defined scope.
More shellfish harvesting classification Thursday 20 April 2006 Classification of shellfish harvesting areas in Scottish waters.
The opening chapters effortlessly of this book guide the reader through the dangerous shoals of classification theory.
The final three books are on solid geometry, and conclude with the construction and classification of the five Platonic solids.
Flexeril contraindications 1 buying online soma what classification of drug is in.
Classification of colic spasmodic colic is the most common type of colic.
Books are arranged on the shelves using a classification scheme, which groups books on a particular subject together with the same number.
Classification of wine By vinification methods Wines may be classified by vinification methods Wines may be classified by vinification methods.
These writers both follow the classification of Haliday, who divided the order into two groups or sub-orders.
It will be sufficient to say here that the classification generally adopted by text-writers is based upon the relations of equity to the common law, of which some explanation is given above.
Medical science further owes to him the classification of new growths on a natural histological basis, the elucidation of leucaemia, glioma and lardaceous tumours, and detailed investigations into many diseases - tuberculosis, pyaemia, diphtheria, leprosy, typhus, &c. Among the books he published on pathological and medical subjects may be mentioned Vorlesungen fiber Pathologic, the first volume of which was the Cellular-pathologic (1858), and the remaining three Die Krankhaften Geschwiilste (1863-67); Handbuch der speziellen Pathologic and Therapie (3 vols., 1854-62), in collaboration with other German surgeons; Gesammelte Abhandlungen zur wissenschaftlichen Medizin (1856); Vier Reden fiber Leben and Kranksein (1862); Untersuchungen fiber die Entwicklung des Schlidelgrundes (1857); Lehre von den Trichinen (1865); Ueber den Hunger-typhus (1868); and Gesammelte Abhandlungen aus dem Gebiete der afentlichen Medizin and der Seuchenlehre (1879).
It may be further defined as the science that treats of the analysis, classification, preparation, composition and delivery of sermons.
If a less arbitrary classification be followed the principal manufacturing industries would be stone manufacture and textiles.
Some clue to this enigma may perhaps be found in the second principle of classification proposed by the present writer at the Congresso Internationale di Scienze Storiche at Rome (Atti del Con gresso, ii) in 1903.
This method of classification, though formally accurate, has slight value in the exact sciences, partly because at every step one of the two groups is merely negatively characterized and therefore incapable of real subdivision; it is useful, however, in setting forth clearly the gradual descent from the most inclusive genus (summum genus) through species to the lowest class (infima species), which is divisible only into individual persons or things.
In classifying methods of generation it is usual to make use of the sexual or non-sexual nature of the reproduction as a primary difference, but a more scientific classification is afforded by the distinction between tissue-cells After Allman, Gymnoblastic Hydroids, by permission of the Council of the Ray Society.
While such a classification may serve its purpose as a sort of index, it must be confessed that the limits of its usefulness are soon reached.
Notwithstanding the form of this classification, Kant himself treats mathematical geography as preliminary to, and therefore not dependent on, physical geography.
The usual classification of islands is into continental and oceanic. The former class includes all those which rise from the continental.
The simple classification employed by Professor James Geikie 3 into mountains of accumulation, mountains of elevation and mountains of circumdenudation, is not considered sufficiently thorough by German geographers, who, following Richthofen, generally adopt a classification dependent on six primary divisions, each of which is subdivided.
The simplest classification is perhaps that of Drude according to climatic zones, subdivided according to continents.
The development of culture is to a certain extent a question of race, and although forming one species, the varieties of mandiffer in almost imperceptible gradations with a complexity defying classification (see Anthropology).
For the history of the classification of birds see the article Ornithology, where also the more important ornithological works are mentioned.
Classification Of Birds Fiirbringer's great work, published in the year 1888 by the Natura Artis Magistra Society of Amsterdam, enabled Gadow not only to continue for the next five years the same lines of morphological research, but also further to investigate those questions which were still left in abeyance or seemed to require renewed study.
The Meteoritic Hypothesis (1890) propounds a comprehensive scheme of cosmical evolution, which has evoked more dissent than approval, while the Sun's Place in Nature (1897) lays down the lines of a classification of the stars, depending upon their supposed temperature-relations.
Ether and alcohol he regarded as substances analogous to and built up on the same type as water, and he further introduced the water-type as a widely applicable basis for the classification of chemical compounds.
The several attempts at system-making by Kaup, from his Allgemeine Zoologie in 1829 to his fiber Classification der Vogel in 1849, were equally arbitrary and abortive; but his Skizzirte Entwickelungs-Geschichte in 1829 must be here named, as it is so often quoted on account of the number of new genera which the peculiar views he had embraced compelled him to invent.
Then we have Selby's Illustrations of British Ornithology, two folio volumes of coloured plates engraved by himself, between 1821 and 1833, with letterpress also in two volumes (8vo, 1825-1833), a second edition of the first volume being also issued (1833), for the author, having yielded to the pressure of the " Quinarian " doctrines then in vogue, thought it necessary to adjust his classification accordingly, and it must be admitted that for information the 6 Copies are said to exist bearing the date 1814.
It was only when, after a close examination of the sternal apparatus of one hundred and thirty species, which he carefully described, that he arrived (pp. 177-183) at the conclusion - astonishing to us who know of L'Herminier's previous results - that the sternum of birds cannot be used as a help to their classification on account of the egregious anomalies that would follow the proceeding - such anomalies, for instance, as the separation of Cypselus from Hirundo and its alliance with Trochilus, and the grouping of Hirundo and Fringilla together.
It is plain that Blyth saw, and perhaps he was the first to see it, that geographical distribution was not unimportant in suggesting the affinities and differences of natural groups (pp. 258, 259); and, undeterred by the precepts and practice of the hitherto dominant English school of Ornithologists, he declared that " anatomy, when aided by every character which the manner of propagation, the progressive changes, and other physiological data supply, is the only sure basis of classification."
On the other hand Oken (Isis, 1842, pp. 39 1 -394), though giving a summary of Nitzsch's results and classification, was more sparing of his praise, and prefaced his remarks by asserting that he could not refrain from laughter when he looked at the plates in Nitzsch's work, since they reminded him of the plucked fowls hanging in a poulterer's shop, and goes on to say that, as the author always had the luck to engage in researches of which nobody thought, so had he the luck to print them where nobody sought them.
The Revue Zoologique for 1847 (pp. 360-369) contained the whole, and enabled naturalists to consider the merits of the author's project, which was to found a new classification of birds on the form of the anterior palatal bones, which he declared to be subjected more evidently than any other to certain fixed laws.
After several minor notices that appeared in journals at various times, Des Murs in 1860 brought out at Paris his ambitious Traite general d'oologie ornithologique au point de vue de la classification, which contains (pp. 529-538) a " Systema Oologicum " as the final result of his labours.
Huxley, to the delight of an appreciative audience, delivered at the Royal College of Surgeons of England a course of lectures on birds, and a few weeks after presented an abstract of his researches to the Zoological Society, in whose Proceedings for the same year it will be found printed (pp. 415-472) as a paper " On the Classification of Birds, and on the taxonomic value of the modifications of certain of the cranial bones observable in that Class."
We restrict the origin of the Ratitae to that great branch of still primitive Carinatae which, after separation of the Ratitae, has further developed into the legion of the Alectoromorphae, notably Tinamiand Galliformes, together with still low Gruiformes (see BIRD, Classification).
We have seen how his classification of substances into elements and compounds, and the definitions which he assigned to these species, have similarly been retained; and how Lavoisier established the law of the "conservation of mass," overthrew the prevailing phlogistic theory, and became the founder of modern chemistry by the overwhelming importance which he gave to the use of the balance.
General Principles The substances with which the chemist has to deal admit of classification into elements and compounds.
Scandium possesses great historical interest, for Cleve showed that it was one of the elements predicted by Mendeleeff about ten years previously from considerations based on his periodic classification of the elements (see Element).
Dulong and Petit's law thus points to the value 114, which is also supported by the position occupied by this element in the periodic classification.
It will be more appropriate here, without giving what would be a needless repetition of considerations, both historical and theoretical, which appear in other articles, to confine ourselves to two general questions, (I) the history of the various schemes of classification, or Morphography, and (2) the consideration of the main tendencies iii the study of zoology since Darwin.
According to its position in the periodic classification of the elements one would expect its atomic weight to be less than that of iodine, instead of approximately equal, and on this account many efforts have been made to isolate another element from tellurium compounds, but none have as yet been successful.
In its chemical relationships tantalum is associated with vanadium, columbium and didymium in a sub-group of the periodic classification.
It is impossible to offer any exhaustive classification of those who, while they rejected the teachings of the old Church, refused at the same time to conform to the particular types of Protestantism which had found favour in the eyes of the princes and been imposed by them on their subjects.
A system of classification for the Phanerogams, or, as they are frequently now called, Spermatophyta (seed-plants), which has been much used in Great Britain and in America, is that of Bentham and Hooker, whose Genera Plantarum (1862-1883) is a descriptive account of all the genera of flowering plants, based on their careful examination.
Altogether, eight orders are recognized in the classification adopted here, the first five of these belonging to the sub-class Exopterygota and the last three to the Endopterygota (see Hexapoda).
In modern practice (see Zoological Nomenclature) systematists no longer regard species as more than as an artificial rank in classification, to be applied chiefly for reasons of convenience, so that the word is reverting to its older logical significance.
A classification of this flora necessitates La Plata, 1900, and " Beitrge zur Kenntnis der Juraund Kreideformation der Cordillere," Palaeontographica, vol.
In his researches, Roscoe showed that the atomic weight of the metal as determined by Berzelius and the formulae given to the oxides were incorrect, and pointed out that the element falls into its natural place in group V of the periodic classification along with phosphorus and arsenic, and not in the chromium group where it had originally been placed.
About this time Buchheim, professor of materia medica in Dorpat from 1846 to 1879, founded the first pharmacological laboratory on modern lines in Europe, and he introduced a more rational classification of drugs than had hitherto been in use, arranging them in groups according to their pharmacological actions.
Existing ' rotation invariant ' texture classification schemes can fail when the 3D textures are rotated.
More Shellfish harvesting classification Thursday 20 April 2006 Classification of shellfish harvesting areas in Scottish waters.
Clinical staging of gastric carcinoma by the TNM classification was found to reflect accurately the prognosis of these patients.
Classification The star ratings shown are based on the latest official inspection correct at October 2004.
The database is searchable by gene name, or by kinase classification at the group, family or subfamily level.
This data is used in a variety of surface texture classification schemes.
They recognize that there is a great variety of living things and understand the importance of classification.
Classification of wine By vinification methods Wines may be classified by vinification methods.
When people think about non pedigree kittens for sale, they think of either kittens that are a mixture of breeds or a specific breed without the paperwork to back up their breed classification.
This clear neutral spirit has no real classification system and may be differentiated by price and alcohol content.
Students also learn the classification of all life including members of the plant kingdom, animal kingdom, and the ecological system in which we all live.
Not much - it's normally just a classification within the school.
Here it will be convenient to adhere to the old classification, which places Pears under Pyrus, Apples under Malus, Beams under Aria, and Mountain Ashes and Service Trees under Sorbus.
In every branch of human effort the mania for hairsplitting and classification is harmful and even impossible, as in the attempt to distinguish between practice and science!
Further classification specifies organic ingredients and labeling guidelines.
Although many people tend to lump these people all into one classification, their defining decade was very different.
The truth of the matter is that criteria and classification for UV protection is not mandatory.
The Australian Office of Film and Literature Classification, which is responsible for video game ratings in that country, has taken away the GTA 3's classification altogether.
The game, published by Electronic Arts, seems to transcend conventional genre classification.
I get the question all the time about the classification levels that are listed on bottles of Cognac and other brandies.
To determine the condition of a tool, most collectors refer to the The Fine Tool Journal Classification System.
A copy of the classification system is provided by Tool Timer in the article A Beginners Guide to Collecting Antique Tools.
The classification criteria are approximately half way down the page.
This rating system is provided just below the Fine Tool Journal Classification System.
The most widely used classification scheme for the vasculitides was first proposed at an international conference in 1994.
Further research in the 1990s led to classification of mitochondrial disorders.
Classification of EDS types was revised in 1997.
This new classification is simpler than the previous classification system and is primarily based on descriptions of the actual symptoms.
About 30 percent of identical twins have this classification, and each twin has its own chorion, amnion, and placenta.
Approximately 68 percent of identical twins are in this classification, and they have a mortality rate of 25 percent.
Only 2 percent of identical twins are in this classification, and they have a mortality rate of greater than 50 percent.
Approximately 60 to 80 percent of all diagnosed cases are in this classification, which usually occurs in children aged five to ten years.
The American Association on Mental Retardation (AAMR) has developed another widely accepted diagnostic classification system for mental retardation.
The AAMR classification system focuses on the capabilities of the retarded individual rather than on the limitations.
Developmentally, peer neglect is not a very stable classification, and many neglected children develop more confidence as they move into classrooms with more familiar or more compatible peers.
Some psychiatrists are critical of the psychiatric classification of gender identity disorder, saying it is more a social stigma.
A number of different classification (staging) systems are used to establish the severity of retinoblastoma and aid in choosing an appropriate treatment plan.
Carbohydrate intolerance is the inability of the small intestine to completely process the nutrient carbohydrate (a classification that includes sugars and starches) into a source of energy for the body.
The terms antibody and immunoglobulin are often used interchangeably, although immunoglobulin refers to the larger classification system for antibodies.
Red blood cell (RBC) indices are calculations derived from the complete blood count that aid in the diagnosis and classification of anemia.
Prisons.The prisons of France, some of them attached to the ministry of the interior, are complex in their classification.
The different kinds of motive power used to actuate cranes - manual, steam, hydraulic, electric - give a further classification.
As in the Gymnoblastea, the difficulty of uniting the hydroid and medusan systems into one scheme of classification is very great in the present state of our knowledge.
Radlkofer (1883) was the first to call attention to the great importance of this method in systematic botany, as providing fresh characters on which to base a natural classification.
Huxley, in 1868, divided the carinate birds into Dromaeo-, Schizo-, Desmo-, and Aegithognathae, an arrangement which for many years had a considerable influence upon classification.
We should be able to construct the pedigree of every group, in other words, the gigantic natural system, but there would be no classification.
The families are those which are enumerated in Garow's classification.
Thus the whole classification becomes a rounded-off phylogenetic system, which, at least in its broad outlines, seems to approach the natural system, the ideal goal of the scientific ornithologist.
The number of described species can now hardly be less than 10o,000, but there is little agreement as to the main principles of a natural classification.
Macleay's classification (1825), which rested principally on the characters of the larvae, is almost forgotten nowadays, but it is certain that in any systematic arrangement which claims to be natural the early stages in the life-history must receive due attention.
Lameere (1900) has suggested three sub-orders, the Cantharidif ormia (including the Phytophaga, the Heteromera, the Rhynchophora and most of the Polymorpha of Sharp's classification), the Staphyliniformia (including the rove-beetles, carrion-beetles and a few allied' amilies of Sharp's Polymorpha), and the Carabidiformia (Adephaga).
Lameere's classification is founded on the number of abdominal sterna, the nervuration of the wings, the number of malpighian tubules (whether four or six) and other structural characters.
Students of the Coleoptera have failed to agree not only on a system of classification, but on the relative specialization of some of the groups which'.
In the classification adopted in this article, the attempt has been made to combine the best points in old and recent schemes, and to avoid the inconvenience of a large heterogeneous group including the vast majority of the families.
This classification is based partly upon special conditions of service, which make some articles more economical to carry than others (with particular reference to the question whether the goods are offered to the companies in car-loads or in small parcels), but chiefly with regard to the commercial value of the article, and its consequent ability to bear a high charge or a low one.
Besides the system of charges thus prescribed in the classification and rate-sheet, each tariff provides for a certain number of special rates or charges made for particular lines of trade in certain localities, independently of their relation to the general system.
A classification may also be made, according to the work for which engines are designed, into passenger engines, goods engines, and shunting or switching engines.
The wings, which are not capable of being folded, are usually transparent, but occasionally pigmented and adorned with coloured spots, blotches or bands; the wing-membrane, though sometimes clothed with minute hairs, seldom bears scales; the wing-veins, which are of great importance in the classification of Diptera, are usually few in number and chiefly longitudinal, there being a marked paucity of cross-veins.
The antennae of Diptera, which are also extremely important in classification, are thread-like in the more primitive families, such as the Tipulidae (daddy-long-legs), where they consist of a considerable number of joints, all of which except the first two, and sometimes also the last two, are similar in shape; in the more specialized families, such as the Tabanidae (horse-flies), Syrphidae (hover-flies) or Muscidae (house-flies, blue-bottles and their allies), the number of antennal joints is greatly reduced by coalescence, so that the antennae appear to consist of only three joints.
Bristles are usually present on the legs, and in the case of many families on the body also; those on the head and thorax are of great importance in classification.
Diptera are divided into some sixty families, the exact classification of which has not yet been finally settled.
This classification has been very generally received, and most later schemes have been modifications of it.
Considerable progress has been made in the classification of the various races which occupy the continent to the west of the great Mongolian region.
It is evident that no permanent classification is possible of what is or is not of economic significance.
Again, the classification of an economic bibliography at once shows how varied has been the character of economic investigation, ranging from the most abstract speculation on the one hand to almost technical studies of particular trades on the other.
The former classification into Holochlamyda, Pneumochlamyda and Siphonochlamyda has been abandoned, as it was founded on adaptive characters not always indicative of true affinities.
As an extreme contrast to this After Westwood, c am odeif orm type, we take the maggot Modern Classification.
Nevertheless, the constant increase of our knowledge of insect forms renders classification increasingly difficult, for gaps in the series become filled, and while the number of genera and families increases, the distinctions between these groups become dependent on characters that must seem trivial to the naturalist who is not a specialist.
His classification was founded mainly on the nature of the wings, and five of his orders - the Hymenoptera (bees, ants, wasps, &c.), Coleoptera (beetles), Diptera (two-winged flies), Lepidoptera (moths and butterflies), and Hemiptera (bugs, cicads, &c.) - are recognized to-day with nearly the same limits as he laid down.
The great advance in modern zoology as regards the classification of the Hexapoda lies in the treatment of a heterogeneous assembly which formed Linnaeus's order Neuroptera.
Brauer in his arrangement of these orders laid special stress on the nature of the metamorphosis, and was the first to draw attention to the number of Malpighian tubes as of importance in classification.
The classification here adopted is based on Sharp's scheme, with the addition of suggestions from some of the most recent authors - especially Bdrner and Enderlein.
Geological History The classification just given has been drawn up with reference to existing insects, but the great majority of the extinct forms that have been discovered can be referred with some confidence to the same orders, and in many cases to recent families.
The first is entitled Externarum et internarum principalium humani corporis Tabulae, &c. while the second, which is the most valuable, is merely appended to the Lectiones Gabrielis Fallopii de partibus similaribus humani corporis, &c., and thus, the scope of each work being regarded as medical, the author's labours were wholly overlooked by the mere naturalhistorians who followed, though Coiter introduced a table, " De differentiis Auium," furnishing a key to a rough classification of such birds as were known to him, and this as nearly the first attempt of the kind deserves notice here.
In his classification of birds Linnaeus for the most part followed Ray, and where he departed from his model he seldom improved upon it.
His attempt at classification was certainly better than that of Linnaeus; and it is rather curious that the researches of the latest ornithologists point to results in some degree comparable with Brisson's systematic arrangement, for they refuse to keep the birds-of-prey at the head of the Class A y es, and they require the establishment of a much larger number of " Orders " than for a long while was thought advisable.
The classification was modified, chiefly on the old lines of Willughby and Ray, and certainly for the better; but no scientific nomenclature was adopted, which, as the author subsequently found, was a change for the worse.
He took many liberties with the details of Linnaeus's work, but left the classification, at least of the birds, as it was - a few new genera excepted.'
In the work just mentioned few details are given; but even the more elaborate classification of birds contained in his Lecons d'anatomie comparee of 1805 is based wholly on external characters, such as had been used by nearly all his predecessors; and the Regne Animal of 1817, when he 1 This was reprinted in 5882 by the Willughby Society.
Unfortunately for him, as will appear in the sequel, it seems not to have occurred to him to use any of the results he obtained as the basis of a classification.
The more important monographs will usually be found cited in the separate articles on birds contained in this work, though some, by reason of changed views of classification, have for practical purposes to be regarded now as general works.
These need not detain us for long, since, however well some of them may have been executed, regard being had to their epoch, and whatever repute some of them may have achieved, they are, so far as general information and especially classification is concerned, wholly obsolete, and most of them almost useless except as matters of antiquarian interest.
The classification was quite new, and made a step distinctly in advance of anything.
In 1816 Vieillot published at Paris an Analyse d'une nouvelle ornithologie elementaire, containing a method of classification which he had tried in vain to get printed before, both in Turin and in London.
The views of neither of these systematizers pleased Temminck, who in 1817 replied rather sharply to Vieillot in some Observations sur la classification methodique des oiseaux, a pamphlet published at Amsterdam, and prefixed to the second edition m i nd.
However, Nitzsch had not as yet seen his way to proposing any methodical arrangement of the various groups of birds, and it was not until some eighteen months later that a scheme of classification in the main anatomical was attempted.
This is a very disappointing performance, since the author observes that, notwithstanding his new classification of birds is based on a study of the form of the sternal apparatus, yet, because that lies wholly within the body, he is compelled to have recourse to such outward characters as are afforded by the 1 From carin g, a keel.
We have already seen that De Blainville, though fully persuaded of the great value of sternal features as a method of classification, had been compelled to fall back upon the old pedal characters so often employed before; but now the scholar had learnt to excel his teacher, and not only to form an at least provisional arrangement of the various members of the Class, based on sternal characters, but to describe these characters at some length, and so give a reason for the faith that was in him.
Two years later Nitzsch, who was indefatigable in his endeavour to discover the natural families of birds and had been pursuing a series of researches into their vascular system, published the result, at Halle in Saxony, in his Observationes de avium arteria carotide communi, in which is included a classification drawn up in accordance with the variation of structure which that important vessel presented in the several groups that he had opportunities of examining.
But it must be observed that the classification of Nitzsch, just given, rests much more on characters furnished by the general structure than on those furnished by the carotid artery only.
For the rest his classification demands no particular remark; but that in a work of this kind he had the courage to recognize, for instance, such a fact as the essential difference between swallows and swifts lifts him considerably above the crowd of other ornithological writers of his time.
His scheme of classification, being as before stated partial, need not be given in detail.
In the same year (1839) another slight advance was made in the classification of the true Passerines.
While furnishing - almost unconsciously, however - additional evidence for overthrowing that classification, there is, nevertheless, no attempt made to construct a better one; and the elaborate tables of dimensions, both absolute and proportional, suggestive as is the whole tendency of the author's observations, seem not to lead to any very practical result, though the systematist's need to look beneath the integument, even in parts that are so comparatively little hidden as birds' feet, is once more made beyond all question apparent.
Indeed he was so much prepossessed in favour of a classification based on the structure of the digestive organs that he could not bring himself to consider vocal muscles to be of much taxonomic use, and it was reserved to Johannes Muller to point out that the contrary was the fact.
Carrying on the work from the anatomical point at which he had left it, correcting his errors, and utilizing to the fullest extent the observations of Keyserling and Blasius, to which reference has already been made, Muller, though hampered by mistaken notions of which he seems to have been unable to rid himself, propounded a scheme for the classification of this group, the general truth of which has been admitted by all his successors, based, as the title of his treatise expressed, on the hitherto unknown different types of the vocal organs in the Passerines.
In the evolution of these laws Dr Cornay had most laudably studied, as his observations prove, a vast number of different types, and the upshot of his whole labours, though not very clearly stated, was such as to wholly subvert the classification at that time generally adopted by French ornithologists.
The same year which saw the promulgation of the crude scheme just described, as well as the publication of the final researches of Muller, witnessed also another attempt at the classification of birds, much more limited indeed in scope, but, so far as it went, regarded by most ornithologists of the time as almost final in its operation.
Classification assumed a wholly different aspect.
Classification for the first time was something more than the expression of a fancy, not that it had not also its imaginative side.
More than this, he entered upon their geographical distribution, the facts of which important subject are here, almost for the first time, since the attempt of Blyth already mentioned, 4 brought to bear practically on classification.
Here we must mention the intimate connexion between classification and geographical distribution as revealed by the palaeontological researches of Alphonse Milne-Edwards, whose magnificent Oiseaux Fossiles de la France a.
Hence it became manifest that a very respectable classification can be found in which characters drawn from these bones play a rather important part.
Unfortunately none of these, however, can be compared for singularity with Archaeopteryx or with some American fossil forms next to be noticed, for their particular It is true that from the time of Buffon, though he scorned any regular classification, geographical distribution had been occasionally held to have something to do with systematic arrangement; but the way in which the two were related was never clearly put forth, though people who could read between the lines might have guessed the secret from Darwin's Journal of Researches, as well as from his introduction to the Zoology of the " Beagle" Voyage.
The former efforts at classification made by Sundevall have already several times been mentioned, and a return to their con sideration was promised.
Hence his efforts, praiseworthy as they were from several points of view, and particularly so in regard to some details, failed to satisfy the philosophic taxonomer when generalizations and deeper principles were concerned, and in his practice in respect of certain technicalities of classification he was, in the eyes of the orthodox, a transgressor.
Sclater published in the Ibis a classification which was mainly a revision of the system of Huxley, modified by the investigations of Garrod and Forbes and by his own large acquaintance with museum specimens.
Reichenow in Die Vogel der zoologischen Garten published a classification of birds with a phylogenetic tree.
Apart from its intrinsic merits as a learned and valuable addition to classification, this work is interesting in the history of ornithology because of the wholesale changes of nomenclature it introduced as the result of much diligence and zeal in the application of the strict rule of priority to the names of birds.
The system of classification adopted in time became so elaborate that many municipalities became isolated, each in a separate class, and the evils of special legislation were revived.
Considerable difficulty is encountered in attempting to draw up a botanical classification of the species of Gossypium.
His name is best known for the share he had in the periodic classification of the elements.
For the morphology and classification of snails, see Gastropoda.
Consequently we are justified in retaining "Ratitae" in our classification, although they are a heterogeneous, not strictly monophyletic, assembly.
To the physicist matter is presented in three leading forms - solids, liquids and gases; and although further subdivisions have been rendered necessary with the growth of knowledge the same principle is retained, namely, a classification based on properties having no relation to composition.
The fundamental chemical classification of matter, on the other hand, recognizes two groups of substances, namely, elements, which are substances not admitting of analysis into other substances, and compounds, which do admit of analysis into simpler substances and also of synthesis from simpler substances.
Carbon was joined with silicon, zirconium and titanium, while boron, being trivalent, was relegated to another group. A general classification of elements, however, was not realized by Frankland, nor even by Odling, who had also investigated the question from the valency standpoint.
It is true that by the distillation of many herbs, resins and similar substances, several organic compounds had been prepared, and in a few cases employed as medicines; but the prevailing classification of substances by physical and; superficial properties led to the correlation of organic and inorganic compounds, without any attention being paid to their chemical composition.
The clarification and spirit of research so clearly emphasized by Robert Boyle in the middle of the 17th century is reflected in the classification of substances expounded by Nicolas Lemery, in 1675, in his Cours de chymie.
Notwithstanding the inconsistency of his allocation of substances to the different groups (for instance, acetic acid was placed in the vegetable class, while the acetates and the products of their dry distillation, acetone, &c., were placed in the mineral class), this classification came into favour.
At the same time, however, he adhered to the classification of Lemery; and it was only when identical compounds were obtained from both vegetable and animal sources that this subdivision was discarded, and the classes were assimilated in the division organic chemistry.
This description, although not absolutely comprehensive, serves as a convenient starting-point for a preliminary classification, since a great number of substances, including the most important, are directly referable to hydrocarbons, being formed by replacing one or more hydrogen atoms by other atoms or groups.
From these nuclei an immense number of derivatives may be obtained, for the hydrogen atoms may be substituted by any of the radicals discussed in the preceding section on the classification of organic compounds.
The development of the theory of crystal structure, and the fundamental principles on which is based the classification of crystal forms, are treated in the article Crystallography; in the same place will be found an account of the doctrine of isomorphism, polymorphism and morphotropy.
Isomorphism is most clearly discerned between elements of analogous chemical properties; and from the wide generality of such observations attempts have been made to form a classification of elements based on isomorphous replacements.
All these varieties were represented at the annual show of the Kennel Club in the autumn of 1905, and at the representative exhibition of America held under the management of the Westminster Kennel Club in the following spring the classification was substantially the same, additional breeds, however, being Boston terriers - practically unknown in England, - Chesapeake Bay dogs, Chihuahuas, Papillons and Roseneath terriers.
The latter were only recently introduced into the United States, though well known in Great Britain as the West Highland or Poltalloch terrier; an application which was made (1900) by some of their admirers for separate classification was refused by the Kennel Club, but afterwards it was granted, the breed being classified as the West Highland white terrier.
Considerable difference of opinion exists with regard to the best classification of the family, some authorities including most of the species in the typical genus Rhinoceros, while others recognize quite a number of sub-families and still more genera.
A complete classification of mathematical sciences, as they at present exist, is to be found in the International Catalogue of Scientific Literature promoted by the Royal Society.
The classification in question was drawn up by an international committee of eminent mathematicians, and thus has the highest authority.
The practical object of the enterprise required that the proportionate quantity of yearly output in the various branches, and that the liability of various topics as a matter of fact to occur in connexion with each other, should modify the classification.
His mode of viewing Christianity does not fit into any classification.
One classification makes three divisions for the epoch, characterized respectively by the existence of the cavebear, the mammoth and reindeer; another, two, marked by the prevalence of the mammoth and reindeer respectively.
The following scheme of classification is based on Beecher's and Schubert's.
As a member of the state Senate he supported the War of 1812 and drew up a classification act for the enrolment of volunteers.
This fact renders their association with the Crustacea impossible, if classification is to be the expression of genetic affinity inferred from structural coincidence.
We have now to offer a classification of the Arachnida and to pass in review the larger groups, with a brief statement of their structural characteristics.
The greater or less evolution and specialization of the metasomatic carapace appears to be the most important basis for classification - but this has not been made use of in the latest attempts at drawing up a system of the Trilobites.
Pocock, assistant in the Natural History departments of the British Museum, for valuable assistance in the preparation of this article and for the classification and definition of the groups of Eu-arachnida here given.
It is hardly possible to form any classification which is not open to some objection.
In any case the classification must be to some extent provisional, since scholars are still divided as to the original language, date and place of composition of some of the books which must come under our classification.'
The interesting problem of the future is - are we to regard this classification as fixed or as merely transitory?
More 1 Brongniart's Essai d'une classification naturelle des reptiles was not published in full till 1803.
Latreille 6 published a new classification of the Vertebrata, which are primarily divided into Haematherma, containing the three classes of Maminifera, Monotremata and A y es; and Haemacryma, also containing three classes - Reptilia, Amphibia and Pisces.
In most cases these subsidiary algebras, as they may be called, are inseparable from the applications in which they are used; but in any attempt at a natural classification of algebra (at present a hopeless task), they would have to be taken into account.
Rating, in maritime vocabulary, is the classification of men according to rank, and was formerly employed to class ships of a navy according to strength.
The classification of ships into six rates, and into rated and non-rated ships, continued during the existence of the old sailing fleets, with modifications in detail.
Systems Of Classification Morphography includes the systematic exploration and tabulation of the facts involved in the recognition of all the recent and extinct kinds of animals and their distribution in space and time.
By the introduction of a method of classification which was due to the superficial Pliny - depending, not on structure, but on the medium inhabited by an animal, whether earth, air or waterWotton is led to associate Fishes and Whales as aquatic animals.
Apart from his special discoveries in the anatomy of plants and animals, and his descriptions of new species, the great merit of Linnaeus was his introduction of a method of enumeration and classification which may be said to have created systematic zoology and botany in their present form, and establishes his name for ever as the great organizer, the man who recognized a great practical want in the use of language and supplied it.
It was in 1812 that Cuvier communicated to the Academy of Sciences of Paris his views on the classification of animals.
Cuvier's His classification as finally elaborated in Le Regne classifi- cation.
The classification adopted by Owen in his lectures (1855) does not adequately illustrate the progress of zoological classifi- knowledge between Cuvier's death and that date, but, such as it is, it is worth citing here.
His most important memoirs, besides that just mentioned, are those on the anatomy and classification of Fishes, on the Caecilians and on the developmental history of the Echinoderms.
It is impossible to enumerate or to give due consideration to all the names in the army of anatomical and embryological students of the middle third of the 19th century whose labours bore fruit in the modification of zoological theories and in the building up of a true classification of animals.
Contemporaneous with these were various schemes of classification which were based, not on a consideration of the entire structure of each animal, but on the variations of a single organ, or on the really non-significant fact of the structure of the egg.
Huxley adopted in his lectures (1869) a classification which was in many respects similar to both of the foregoing, but embodied improvements of his own.
We now arrive at the period when the doctrine of organic evolution was established by Darwin, and when naturalists, being convinced by him as they had not been by the transmutationists of fifty years' earlier date, were compelled to take an entirely new view of the significance of all attempts at framing a " natural " classification.
From time to time efforts were made by those who believed that the Creator must have followed a symmetrical system in his production of animals to force one or other artificial, neatly balanced scheme of classification upon the zoological world.
That doctrine took some few years to produce its effect, but it became evident at once to those who accepted Darwinism that the natural classification of animals, after which collectors and anatomists, morphologists, philosophers and embryologists had been so long striving, was nothing more nor less than a genealogical tree, with breaks and gaps of various extent in its record.
The whole " system " or scheme of classification was termed a genealogical tree (Stammbaum); the main branches were termed " phyla," their branchings " sub-phyla "; the great branches of the sub-phyla were termed " cladi," and the " cladi " divided into " classes," these into sub-classes, these into legions, legions into orders, orders into sub-orders, suborders into tribes, tribes into families, families into genera, genera into species.
In the edition of the Natiirliche Schopfungsgeschichte published in 1868 he made a great advance in his genealogical classification, since he now introduced the results of the extraordinary activity in the study of embryology which followed on the publication of the Origin of Species.
Balfour, and produced the profoundest modifications in classification.
Another important factor in the present condition of zoological knowledge as represented by classification is the doctrine of degeneration propounded by Anton Dohrn.
The immediate result was, as pointed out above, a reconstruction of the classification of animals upon a genealogical basis, and an investigation of the individual development of animals in relation to the steps of their gradual building up by cell-division, with a view to obtaining evidence of their genetic relationships.
The most instructive classification of the " variations " exhibited by fully formed organisms consists in the separation in the first place of those which arise from antecedent congenital, innate, constitutional or germinal variations from those which arise merely from the operation of variation of the environment or the food-supply upon normally constituted individuals.
To meet this exigency, Zarlino proposed that for the lute the octave should be divided into twelve equal semitones; and after centuries of discussion this system of "equal temperament" has, within the last thirty-five years, been universally adopted as the best attainable for keyed instruments of every description.3 Again, Zarlino was in advance of his age in his classification of the ecclesiastical modes.
Otric, suspecting that Gerbert erred in his classification of the sciences, sent one of his own pupils to Reims to take notes of his lectures, and, finding his suspicions correct, accused him of his error before Otto II.
Details of the morphology of plants will be found in the articles relating to the chief groups of plants, those of animals in the corresponding articles on groups of animals, while the classification of animals adopted in this work will be found in the article ZOOLOGY.
This classification is ingenious and convenient as far as it goes, but it seems probable that the trouser, which also has the waist as its point of attachment, may itself be a further development of the girdle.
It reported favourably, especially on the use of the measurements for primary classification, but recommended also the adoption in part of a system of "finger prints" as suggested by Francis Galton, and already practised in Bengal.
It is largely to researches on the bone marrow that we owe our present knowledge of the origin and the classification of the different cellular elements of the blood, both erythrocytes or red corpuscles, and the series of granular leucocytes or white corpuscles.
More importance is to be attached to his Nosology or Classification of Diseases.
Cullen drew out a classification of great and needless complexity, the chief part of which is now forgotten, but several of his main divisions are still preserved.
We must retrace our steps a little to enumerate several distinguished names which, from the nature of the case, hardly admit of classification.
With the melting of the ice the more daring spirits dashed into the new current with such ardour that for them all traditions, all institutions, were thrown into hotchpot; even elderly and sober physicians took enough of the infection to liberate their minds, and, in the field of the several diseases and in that of post-mortem pathology, the hollowness of classification by superficial resemblance, the transitoriness of forms, and the flow of processes, broke upon the view.
In his classification it was included in the same genus as the orang-utan; and it has recently been suggested that the name Simia pertains of right to the chimpanzee rather than to the orang-utan.
Looking somewhat deeper at the sources from which Old English law was derived, we shall have to modify our classification to some extent, as the external forms of publication, although important from the point of view of historical criticism, are not sufficient standards as to the juridical character of the various kinds of material.
Classification of the Cestoda Merozoa [[Order I]].
Havana cigars are, as regards form, classification, method of putting up and nomenclature, the models followed by manufacturers of all classes of the goods.
In its chemical relations, titanium is generally tetravalent, and occurs in the same sub-group of the periodic classification as zirconium, cerium and thorium.
The first step in this direction is to arrange scientific method and positive knowledge in order, and this brings us to another cardinal element in the Comtist system, the classification of the sciences.
Comte's principle of classification is that the dependence and order of scientific study follows the dependence of the phenomena.
Comte's classification of the sciences has been subjected to a vigorous criticism by Herbert Spencer.
The isomerism which occurs as soon as the molecule contains a few carbon atoms renders any classification based on empirical molecular formulae somewhat ineffective; on the other hand, a scheme based on molecular structure would involve more detail than it is here possible to give.
The classification of the animal kingdom is dealt with in the article ZOOLOGY.
The rapid growth of literature in the 16th century compels him to resort to a classification of subjects.
The main median nervure, and usually also the sub-costal become united with the radial, while the branches of radial, median and cubital nervures pursuing a transverse or recurrent course across the wing, divide its area into a number of areolets or " cells," that are of importance in classification.
In his recent classification Ashmead (1901) recognizes seventy-nine families arranged under eight " super-families."
The voyage of the " Challenger " supplied for the first time the nucleus of a collection of deep-sea deposits sufficient to serve as the basis for comprehensive classification and mapping.
The classification of the different kinds of coal may be considered from various points of view, such as their chemical composition, their behaviour when subjected to heat aa s sifica= or when burnt, and their geological position and iron.
As the amount of ash varies very considerably in different coals, and stands in no relation to the proportion of the other constituents, it is necessary in forming a chemical classification to compute the results of analysis after deduction of the ash and hygroscopic water.
Coal as raised from the pit is now generally subjected to some final process of classification and cleaning before being despatched to the consumer.
As regards classification, the first group is that of the Pecora, or Cotylophora, in which the cheek-teeth are selenodont, but there are no upper incisors or canine-like premolars, Pecora.
Although disposed at first to divide the various documents into three classes, he finally adopted a classification into two - the African or older family of documents, and the Asiatic, or more recent class, to which he attached only a subordinate value.
His idea of applying the natural history method of classification to psychical phenomena gave scientific character to his work, the value of which was enhanced by his methodical exposition and his command of illustration.
There is, however, a radical difference between the two systems. The standpoint of the Aristotelian classification is the predication of one universal concerning another.
This classification, though it is of high value in the clearing up of our conceptions of the essential contrasted with the accidental, the relation of genus, differentia and definition and so forth, is of more significance in connexion with abstract sciences, especially mathematics, than for the physical sciences.
Apart from one or two of the greatest minds, notably Dante, what appealed to the thinkers of the middle ages was not the idea of reality as a progressive self-revelation of an inner principle working through nature and human life, but the formal principles of classification which it seemed to offer for a material of thought and action given from another source.
With the increase of the city the operation grew in importance, and was followed by an official lustruni, or purificatory sacrifice, offered on behalf of the people by the censors or functionaries in charge of the classification.
Nor should it be forgotten that the internal classification and the combinations of the above subjects are also matters to be treated upon some uniform plan, if the full value of the statistics is to be extracted from the raw material.
In 1800 and 1810 the same classification was preserved, except that five age-groups instead of two were given for free white males and the same five were applied also to free white females.
In 1820 a sixth age class was introduced for free white males, an age classification of four periods was applied to the free coloured and the slaves of each sex, and the number of aliens and of persons engaged in agriculture, in manufactures and in commerce was called for.
It was also the first American census to give a line of the schedule to each person, death or establishment enumerated, and thus to make the returns in the individual form indispensable for a detailed classification and compilation.
The above classification relates to methods.
His chief works were First Lines of the Practice of Physic (1774); Institutions of Medicine (1770); and Synopsis Nosologicae Medicae (1785), which contained his classification of diseases into four great classes - (t) Pyrexiae, or febrile diseases, as typhus fever; (2) Neuroses, or nervous diseases, as epilepsy; (3) Cachexiae, or diseases resulting from bad habit of body, as scurvy; L and (4) Locales, or local diseases, as cancer.
This classification of the members into those who were in full communion and those who belonged only to the " Half Way Covenant " was vigorously attacked by Jonathan Edwards, but it was not abolished until the early years of the 19th century.
Philosophy itself is with him classification and consideration of ideas.
For the classified service of the state and of the minor civil divisions, except cities, the commission makes rules (subject to the governor's approval and to statutory and constitutional provisions) governing the classification of offices, the examination of candidates for office, and the appointment and promotion of employees.
A small deduction should be made from this apparent increase to allow for a changed system of classification.
According to the 1904 census classification the " aboriginal inhabitants" numbered in that year 229,149.
Any division or classification of states must be imperfect.
Waddell (De Pontibus, New York, 1898) proposes to arrange railways in seven classes, according to the live loads which may be expected from the character of their traffic, and to construct bridges in accordance with this classification.
The first thing noticeable about him is that he defies all customary and mechanical classification.
The Laksana Phra Thamasat, the Phra Tamra, Phra Tamnon, Phra Racha Kamnot and Inthapat are ancient works setting forth the laws of the country in their oldest form, adapted from the Dharmacastra and the Classification of the Law of Manu.
Plants which were strikingly alike were placed together, but there was at first little attempt at systematic classification.
In 1690 Rivinus 2 promulgated a classification founded chiefly on the forms of the flowers.
A new era dawned on botanical classification with the work of Antoine Laurent de Jussieu (1748-1836).
Robert Brown (1773-1858) was the first British botanist to support and advocate the natural system of classification.
The study of the anatomy and physiology of plants did not keep pace with the advance in classification.
His followers were chiefly engaged in the arrangement and classification of plants, and while descriptive botany made great advances the physiological department of the science was neglected.
Soon after the promulgation of Linnaeus's method of classification, the attention of botanists was directed to the study of Cryptogamic plants, and the valuable work of Johann Hedwig (1730-1799) on the reproductive organs of mosses made its appearance in 1782.
Thorell's classification (1859) of Gnathostonta, Poecilostoma, Siphonostoma, based on the mouth-organs, was long followed, though almost at the outset shown by Claus to depend on the erroneous supposition that the Poecilostoma were devoid of mandibles.
Moreover usage varies slightly as regards the limits of the three main divisions, but the accompanying table shows the most usual classification, naming the principal groups within each, and distributing them according to the powers to which they are subject.
The municipalities are divided into six classes according to population, a classification which permits considerable special local legislation in spite of the constitutional inhibition.
The general appearance is too misleading for the classification of the Lacertae.
Materials accumulated far more rapidly, however, than the power of generalization and classification.
Able as von Meyer was, his classification of the Reptilia failed because based upon the single adaptive characters of foot structure.
In Kowalevsky's Versuch einer natiirlichen Classification der Fossilen Hufthiere (1873) we find a model union of detailed inductive study with theory and working hypothesis.
From the stomach, canals arise termed the radial canals (r.c.); typically four in number, they run in a radial direction to the edge 2 For other variations of the medusa, often of importance for systematic classification, see Hydromedusae and Scyphomedusae.
This classification of the Nahuatlac tribes has a meaning and value.
It is probable that no satisfactory classification of the Trilobites will be proposed until the limbs of most of the genera have been examined.
We distinguish between animate and inanimate nature, but this classification has no meaning for the savage.
The term is synonymous with Cryptogams, by which it was replaced in later systems of classification.
The classification in the right-hand column of this table is not applicable in detail to regions remote from New York.
This older classification, which has little support except that which is traditional, is still adhered to by many geologists; hut the fact seems to be that the system is set off from the Pennsylvanian (Upper Carboniferous) more sharply than the Cambrian is from the Ordoviciao, the Silurian from the Devonian, or the Devonian from the Mississippian.
This classification is based almost wholly on the fossils, for there seems to be little physical reason for the differentiation of the Oligocene anywhere on the continent.
The number and classification of these departments vary widely in the different cities.
A chemical classification of alkaloids is difficult on account of their complex constitution.
The following classification is simple and convenient; the list of alkaloids makes no pretence at being exhaustive.
The former classification based on these differences in the adductor muscles is now abandoned, having proved to be an unnatural one.
Both works arrive at it from the classification of categories, which is the same in both; except that in the former the categories are treated rather as a logical classification of names signifying things, in the latter rather as a metaphysical classification of things.
In neither, however, are they a grammatical classification of words by their structure; and in neither are they a psychological classification of notions or general conceptions (voi uara), such as they afterwards became in Kant's Critique and the post-Kantian idealism.
This is the real order of Aristotle's system, based on his own theory and classification of sciences.
So far from coming first, Logic comes nowhere in his classification of science.
He really left the Peripatetics to combine his scattered discourses and treatises into a system, to call it logic, and logic Organon, and to put it first as the instrument of sciences; and it was the Stoics who first called logic a science, and assigned it the first place in their triple classification of science into logic, physics, ethics.
The Analytics then, which from the beginning claims to deal with science, is a science of sciences, without however forming any part of the classification.
But if classification is to express relationship, it is impossible to associate in the same order families whose kinship to insects of other orders is nearer than their kinship to each other.
The place which it almost at once took among scientific scholars in Great Britain and throughout Europe was a recognition of the great advance which it represented in the use and classification of ancient authorities.
It is a member of the sixth group in the periodic classification of the elements, being included in the natural family of elements containing molybdenum, tungsten and uranium.
Further details in regard to this, the last revolution in Molluscan classification, will be found in the article Polyzoa.
All rodents are vegetable-feeders, and this uniformity in their food and in the mode of obtaining it, namely by gnawing, has led to that general uniformity in structure observable throughout the group; a feature which renders their classification difficult.
Some diversity of view obtains among naturalists with regard to the classification of the order; the scheme here followed being the one adopted (with some modifications of nomenclature) by Professor Max Weber in his Sliugethiere.
In 1899 Dr Forsyth Major proposed a classification of the family in which a number of species were grouped with the spiny rabbit in the genus Caprolagus, whilst Oryctolagus was taken to include not only the common rabbit, but likewise the Cape hare.
The object of the provision, however, has been in a large measure nullified by the system of city classification, under which Philadelphia is the only city of the first class.
For convenience of classification we may include in Khamdo a long strip of country extending along the northern border of the Lhasa territory of Lhorong jong and Larego as far as Tengri Nor, and bounded to the north by the Dang-la mountains, which is designated by Tibetans as Gyade or " the Chinese province."
Those who wish to follow out the classification in detail should refer to some of the recent monographs mentioned below in the bibliography.
The perithecium is very constant in form and since the gonidia take no part variations are of value in classification some more details may be added.
The classification of lichens is unique in the fact that chemical colour reactions are used by many lichenologists in the discrimination of species, and these reactions are included in the specific diagnoses.
Considerations such as these should make one very wary in placing reliance on these colour reactions for the purposes of classification.
A brief outline of a system of classification, mainly that of Zahlbruckner as given in Engler and Prantl's Pjlanzenfamilien, is outlined below.
In Europe, the system is very completely developed in the British Isles, where was made the first successful attempt at a classification of its various members, although at a somewhat earlier date Omalius d'Halloy had recognized a terrain bituminifere or coal-bearing series in the Belgian region.
Whether a spore results from the sexual union of two similar gametes (zygospore) or from the fertilization of an egg-cell by the protoplasm of a male organ (oospore); or is developed asexually as a motile (zoospore) or a quiescent body cut off from a hypha (conidium) or developed along its course (oidium or chlamydospore), or in its protoplasm (endospore), are matters of importance which have their uses in the classification and terminology of spores, though in many respects they are largely of academic interest.
The real difficulty of classification of the fungi lies in the polyphyletic nature of the group. There is very little doubt that the primitive fungi have been derived by degradation from the lower algae.
A natural classification on these lines would obviously be very complicated, so that in the present state of our knowledge it will be best to retain the three main groups mentioned above,.
The classification of the Mucorini depends on the prevalence and characters of the conidia, and of the sporangia and zygospores - e.g.
This classification was based on carbon-content, or on the properties which it gave.
This classification, though it helps to give a general idea of the subject, yet like most of its kind cannot be applied rigidly.
Some odd lots of skins arrive designated simply as "sundries," so no classification is possible, and this will account for the absence of a few names of skins of which the imports are insignificant in quantity, or are received direct by the wholesale merchants.
Early writers on natural history used the term in its vague logical sense without limiting it to a special category in the hierarchy of classification.
Linnaeus' invention of binomial nomenclature for designating species served systematic biology admirably, but at the same time, by attaching preponderating importance to a particular grade in classification, crystallized the doctrine of fixity.
The lower grades in classification such as sub-species and varieties on the one hand, and the higher grades on the other, such as genera and families, were admitted to be human conceptions imposed on the living world, but species were concrete, objective existences to be discovered and named.
Charles Darwin found the conception of species so definite and fixed that he chose for the title of his great book (1859) the words On the Origin of Species by Means of Natural Selection, although his exposition of evolution applied equally to every grade in classification.
The word "species" now signifies a grade or rank in classification assigned by systematists to an assemblage of organic forms which they judge to be more closely interrelated by common descent than they are related to forms judged to be outside the species, and of which the known individuals, if they differ amongst themselves, differ less markedly than they do from those outside the species, or, if differing markedly, are linked by intermediate forms. It is to be noted that the individuals may themselves be judged to fall into groups of minor rank, known as sub-species or local varieties, but such subordinate assemblages are elevated to specific rank, if they appear not to intergrade so as to form a linked.
Table A following shows the classification of goods adoptec before the tariff revision of 1906.
Forms. - Various schemes of classification have been proposed, but none has met with universal acceptance; the following are at least the principal types.
Rumanians These allotments were slightly modified at the polls by the victory of some Social Democratic candidates not susceptible of strict racial classification.
A classification of the groups in the new Chamber presents many difficulties, but the following statement is approximately accurate.
The plants, 626 in number, are enumerated alphabetically, but a system of classification differing little from Caspar Bauhin's is sketched at the end of the book; and the notes contain many curious references to other parts of natural history.
The first two editions of the Catalogus plantarum Angliae (1670, 1677) were likewise arranged alphabetically; but in the Synopsis stirpium Britannicarum (1690, 1696, also re-edited by Dillenius, 1724, and by Hill, 1760) Ray applied the scheme of classification which he had by that time elaborated in the Methodus and the Historia plantarum.
The greatest merit of this book is the use of the number of cotyledons as a basis of classification; though it must be remembered that the difference between the monocotyledonous and dicotyledonous embryo was detected by Nehemiah Grew.
At this time he based his classification, like Caesalpinus, chiefly upon the fruit, and he distinguished several natural groups,, such as the grasses, Labiatae, Umbelliferae and Papilionaceae.
The classification of the Methodus was extended and improved in the Historia plantarum, but was disfigured by a large class of Anomalae, to include forms that the other orders did not easily admit, and by the separation of the cereals from other grasses.
For accounts of Ray's system of classification, see Cuvier, Lecons hist.
But here, too, the preliminary classification of the documents is beset with doubt.
In the arrangement of the separate sections, a classification according to contents was impracticable because of the variety of subjects often dealt with in one sura.
Another division of the country is into Lower, Middle and Upper Egypt, Middle Egypt in this classification being the district between Cairo and Assiut.
The remains of Old Coptic, though very instructive in their marked peculiarities, are as yet too few for definite classification.
This control was most often exercised by cancelling their classification as second-class matter entitled to low mailing rates.
It might be mentioned here that the whole group of the Fungi (q.v.),with its many thousands of species, is now generally regarded as having been derived from algae, and the system of classification of fungi devised by Brefeld is based upon this belief.
Further discussion of the general characters of algae will be deferred in order to take a brief survey of the subdivisions of the group. For this purpose there will be adopted the classification of algae into four sub-groups, founded on the nature the.
But American extinct types appear to indicate signs of intimate relationship between antelopes, prongbuck and deer, and it may be necessary eventually to amend the current classification.
This should be useful for establishing the date and classification of the earlier finds, which are in the British Museum.
He assisted Sir Wyville Thomson in the examination and classification of the collections of the "Challenger" exploring expedition, and wrote the Review of the Echini (2 vols., 1872-1874) in the reports.
Classification of this literature by traditional subdivision into genres is difficult, and, at the best, unprofitable.
The enforced adoption of new names makes it easy to lose the historical identity of many who really belonged to the Minster Anabaptists, and, on the other hand, has led to the classification of many with the Munster sect who had no real connexion with it.
Oxygen is a member of the sixth group in the periodic classification, and consequently possesses a maximum valency of six.
In 1905 the iron and steel product had increased in value since 1900 44.9%, to $ 8 7,35 2, 7 61; the foundry and machine shop products 25.2%, to $79,9 61, 4 82; and the wire product showed even greater increase, largely because of a difference of classification in the two censuses, the value in 1905 being $14,099,566, as against $2,879,188 in 1900, showing an increase of nearly 390%.
The element of chance, which prevails in the region on either side of the border between pass and failure, obviously prevails equally on either side of the border between " classes," where candidates are classified; it has been suggested by Dr Schuster that numerical order should accompany classification so as to avoid the creation of an artificial gap between the last candidate in one class and the highest in the next.
To metamorphosis he only allowed a logical value, as explaining the natural classification; the only real, existent metamorphosis he saw in the development of the individual from its embryonic stage.
Corresponding to this division is the classification of the single arts.
As for the classification of sophistical methods, so for their criticism, the testimony of Plato is all-important.
He describes the classification of the people, dividing them, however, into seven castes instead of four, namely, philosophers, husbandmen, shepherds, artisans, soldiers, inspectors and the counsellors of the king.
He also studied the alkaloids and organic acids, introduced a classification of the metals according to the facility with which they or their sulphides are oxidized by steam at high temperatures, and effected a comparison of the chemical composition of atmospheric air from all parts of the world.
Ptolemy's classification has been adopted as the basis of the more exactly quantitative modern system.
The recognition of stars is primarily dependent on their brightness or " magnitude "; and it is clear that stars admit of classification on this basis.
Various schemes of classification of spectra have been used.
Sec±hi (1863-1867) who distinguished four " types "; subsequent research, whilst slightly modifying, has in the main confirmed this classification.
Apart from these considerations, the chief modification in the classification introduced by more recent investigators has been to separate Secchi's Type I.
In its salts, thorium is tetravalent, and in the periodic classification it occurs in the same sub-group as titanium, cerium and zirconium.
Thus an act which provided for the classification of prisoners had remained a dead letter; even the separation of the males from the females was not a universal rule.
In 18 3 a select committee of the House of Commons went into the whole subject of secondary punishment and reported that, as the difficulties in the way of an effective classification of prisoners were insurmountable, they were strongly in favour of the confinement of prisoners in separate cells, recommending that the whole of the prisons should be altered accordingly and the expense borne by the public exchequer.
Since then, steps have been taken in the classification of convicts when undergoing sentence with a view to dealing more effectually with habitual criminals.
Further modifications have been introduced from time to time in the British penal system, tending mostly to milder discipline, more intelligent classification of prisoners and a certain amelioration of their lot.
Other measures are set forth in the new classification of convicts, prescribed by the secretary of state in the rules submitted by him to the House of Commons in 1904.
While the occasional services, even when agricultural, in no way established a presumption of villenage, and many socmen, freemen and holders by serjeanty submitted to them, agricultural week-work was primarily considered as a trait of villenage and must have played an important part in the process of classification of early Norman society.
While the manorial system was in full force this contrast led to a classification of holdings and affected the whole position of people on the land.
The plants and animals await study and classification.
Its associations, accordingly, are to the modern ear almost inevitably those of a doctrine of classification only.
In his definite classification of the sciences,'" into First Philosophy, Mathematics and Physics, it has no place.
It is what in one direction gave the now familiar classification of parts of speech, in the other that of thought-categories underlying them.
With Theophrastus, accordingly, in his botanical inquiries, for example, the alternatives of classification, the normal sequence of such and such a character upon such another, the conclusion of rational probability, are what counts.
If Alexander is responsible for such doctrines as that of the intellectus acquisitus, it is to Porphyry, with his characteristically Platonist preference for the doctrine of universals, and for classification, that we owe the scholastic preoccupation with the realist controversy, and with the quinque votes, i.e.
So again in determining the " import " of propositions, it is no accident that in all save existential propositions it is to the familiar rubrics of associationism - co-existence, sequence, causation and resemblance - that he refers for classification, while his general formula as to the conjunctions of connotations is associationist through and through.
The first task of logic is to distinguish and group such concepts according to their marks, and from their classification there naturally follows their connexion in judgment.
According to a second classification, Christianity maybe placed among the " individual " religions, since it traces its origin, like Islam and Buddhism, to an individual as its founder.
The classification of groups of " Western " witnesses has already begun.
The first systematic classification of elementary combinations in mechanism was that founded by Monge, and fully developed by Lanz and Btancourt, which has been generally received, and has been adopted in most treatises on applied mechanics.
But that classification is founded on the absolute instead of the comparative motions of the pieces, and is, for that reason, defective, as Willis pointed out in his admirable treatise On the Principles of Mechanism.
Williss classification is founded, in the first place, on comparative motion, as expressed by velocity ratio and directional relation, and in the second place, on the mode of connection of the driver and follower.
A short description of this system is given in 80, but in the present article the principle of Williss classification is followed mainly.
The arrangement is, however, modified by taking the mode of connection as the basis of the primary classification, and by removing the subject of connection by reduplication to the section of aggregate combinations.
Willis adopts another classification founded on the objects of the combinations, which objects he divides into two classes, viz.
It is seldcm that one of these effects is produced without at the same time producing the other; but the classification of Willis depends upon which of those two effects, even supposing them to occur together, is the practical object of the mechanism.
The frequent mention in the Scholia of " better " and inferior " texts may indicate a classification made by him or by the general opinion of critics.
When we leave the higher circles of the twice-born, the difficulty of finding a uniform basis of classification becomes apparent.
Not all questions of classification internal to this division are yet finally settled.
Among the Lithodinea, or stone crabs, besides important readjustments of classification (Bouvier, 1895, 1896), should be FIG.
On the other side, he addressed himself to the analysis of man considered as a political being, to the anatomy of constitutions and the classification of governments, to the study of motives underlying public action, the secrets of success and the causes of failure in the conduct of affairs.
In the fields of classical learning the students of the Low Countries broke new ground chiefly by methodical collection, classification and comprehensive criticism of previously accumulated stores.
This classification of the Medoc growths became necessary owing to the great variety of qualities produced and the distinct characteristic excellence of the individual vintages.
This general classification, which was made by a conference of brokers in 1855 as a result of many years of observation dating back to the 18th century, is still very fairly descriptive of the average merit of the wines classified.
There is no official classification of the Burgundy wines, but the following is a list comprising some of the finest growths in geographical order, from north to south, together with the localities in or near which they are situated.
In Jerez itself a different classification, namely that according to quality and not age, exists, which, however, is only employed locally.
Thanks to the combined efforts of a great number of scholars, the classification of the hagiographic texts has in recent years made notable progress.
The famous classification' on which this survey proceeds is based upon an analysis of the faculties and objects of human knowledge.
Bacon's grand motive in his attempt to found the sciences anew was the intense conviction that the knowledge man ' The division of the sciences adopted in the great French Encyclopedie was founded upon this classification of Bacon's.
This discussion, though strictly speaking extraneous to the scheme, has always been looked upon as a most important part of his philosophy, and his name is perhaps as much associated with the doctrine of Idols (Idola) as with the theory of induction or the classification of the sciences.
The classification in the Organum, however, not only has the author's sanction, but has received the stamp of historical acceptation; and comparison of the earlier notices, though a point of literary interest, has no important philosophic bearing.
Like his classification of causes, and in some degree his notion of form itself, it comes from Aristotle.
For a long series of suggested bases of classification see Raoul de la Grasserie, Des Religions Comparees au Point de Vue Sociologique (1899), chap. xii.; cf.
That he anticipated in any manner the inductive philosophy cannot be contended; his botanical studies did not lead him, like his contemporary Konrad von Gesner, to any idea of a natural system of classification, and he rejected with the utmost arrogance and violence of language the discoveries of Copernicus.
Cohn's brilliant researches, the chief results of which were published at various periods between 1853 and 1872; Cohn's classification of the bacteria, published in 1872 and extended in 1875, has in fact dominated the study of these organisms almost ever since.
The difficult subject of the classification of bacteria dates ' The difficulties presented by such minute and simple organisms as the Schizomycetes are due partly to the few " characters " which they possess and partly to the dangers of error in manipulating them; it is anything but an easy matter either to trace the whole development of a single form or to recognize with certainty any one stage in the development unless the others are known.
Numerous attempts have been made to construct schemes of classification based on the power of growing colonies _ ?
Although much progress has been made in determining the value and constancy of morphological characters, we are still in need of a sufficiently comprehensive and easily applied scheme of classification, partly owing to the existence in the literature of imperfectly described forms, the life-history of which is not yet known, or the microscopic characters of which have not been examined with sufficient accuracy and thoroughness.
Of these systems, which alone are available in any practical scheme of classification, the two most important and most modern are those of Fischer and Migula.
In the above-given classification, the Scyphomedusae, formerly included with the Hydromedusae as Hydrozoa, are placed nearer the Anthozoa.
Under the revised constitution of 1908 the former classification of cities into four classes and the practice of granting special charters were abolished, and the legislature is required to provide by general laws for the incorporation of cities and villages; "such general laws shall limit their rate of taxation for municipal purposes and restrict their powers of borrowing money and contracting debts."
His great work Asia polyglotta (Paris, 1823 and 1831, with Sprachatlas) not only served as a résumé of all that was known on the subject, but formed a new departure for the classification of the Eastern languages, more especially those of the Russian Empire.
Another important paper is his "Classification of Loci" (1878).
Among his most remarkable works may be mentioned his ten memoirs on quantics, commenced in 1854 and completed in 1878; his creation of the theory of matrices; his researches on the theory of groups; his memoir on abstract geometry, a subject which he created; his introduction into geometry of the "absolute"; his researches on the higher singularities of curves and surfaces; the classification of cubic curves; additions to the theories of rational transformation and correspondence; the theory of the twenty-seven lines that lie on a cubic surface; the theory of elliptic functions; the attraction of ellipsoids; the British Association Reports, 1857 and 1862, on recent progress in general and special theoretical dynamics, and on the secular acceleration of the moon's mean motion.
The Cork Butter Exchange, where classification of the various qualities is carried out by branding under the inspection of experts, was important in the early part of the 17th century, and an unbroken series of accounts dates from 1769 when the present market was founded.
It is unnecessary to insist on the purely speculative character of the conclusions to be reached in this way, so long as they cannot be checked by the results of palaeontology, but, when this is recognized, such speculation is not only legitimate but necessary as a basis on which to build a natural classification.
It is to be noted, however, that the Trilobita, which, according to the classification here adopted, are dealt with under Arachnida, are not very far removed, except in such characters as the absence of a shellfold and of eye-stalks, from the primitive Crustacean here sketched.
It may be useful to give here a synopsis of the classification adopted in this encyclopaedia, noting that, for convenience of treatment, it has been thought, necessary to adopt a grouping not always expressive of the most recent views of affinity.
Davis has elaborated a theory of river classification, and a scheme of the origin of surfacefeatures which is attractive in its simplicity.
That he did not deny the divinity of Christ he proved in The Character of Jesus, forbidding his possible Classification with Men (1861).
These prescriptions are marked by a conscientious classification based on considerations of material, size and number; but they lose themselves in an exaggerated casuistry.
Linnaeus's primarily zoological classification of man did not, however, suit the philosophical opinion of the time, which responded more readily to the systems represented by Buffon, and later by Cuvier, in which the human mind and soul formed an impassable wall of partition between him and other mammalia, so that the definition of man's position in the animal world was treated as not belonging to zoology, but to metaphysics and theology.
On these grounds Huxley, restoring in principle the Linnean classification, desired to include man in the order of Primates.
The anthropological classification of mankind is thus zoological in its nature, like that of the varieties or species of any other animal group, and the characters on which it is based are in great measure physical, though intellectual and traditional peculiarities, such as moral habit and language, furnish important aid.
Classification of races on cranial measurements has long been attempted by eminent anatomists, and in certain cases great reliance may be placed on such measurements.
Were the race-characters constant in degree or even in kind, the classification of races would be easy; but this is not so.
On the whole, Huxley's division probably approaches more nearly than any other to such a tentative classification as may be accepted in definition of the principal varieties of mankind, regarded from a zoological point of view, though anthropologists may be disposed to erect into separate races several of his widely-differing sub-races.
Although the three divisions of savage, barbaric, and civilized man do not correspond at all perfectly with the Stone, Bronze, and Iron Ages, this classification of civilization has proved of extraordinary value in arranging in their proper order of culture the nations of the Old World.
Direct knowledge of the tribes who made them is scanty, but implements so similar in make and design having been in use in North and South America until modern times, it may be assumed for purposes of classification that the Neolithic peoples of the New World were at a similar barbarous level in industrial arts, social organization, moral.
By the Wallace Act of the state legislature in 1874 a form of government was provided for cities of three classes, and Pittsburg became a city of the second class (population between 10o,000 and 300,000); under the act of 1895 a new classification was made, under which Pittsburg remains in the second class.
Yet the first attempts at a classification of plants recognized and separated a group of Gramina, and this, though bounded by nothing more definite than habit and general appearance, contained the Gramineae of modern botanists.
The great uniformity among the very numerous species of this vast family renders its classification very difficult.
Hence, though, like Plato, Speusippus (4) studied the differences of natural products (5) with a view to classification, he did not agree with Plato in his conception of the significance of the results thus obtained; that is to say, while to Plato the definition derived from the study of the particulars included in a natural kind was an approximate definition of the idea in which the natural kind originated, to Speusippus the definition was a definition of the particulars studied, and, strictly speaking, of nothing else.
The family Araucarieae, represented by Araucaria and Agathis, should perhaps be separated as a special class and a rearrangement of other genera more in accord with a natural system of classification will soon be possible; but for the present its twofold subdivision may be retained.
There are eight other living genera, which may be classified as follows Classification.
It is a classification for convenience' sake, adopted upon a rough observation of conspicuous, or apparently conspicuous, differences in the mode of levying taxes, and nothing more.
Classification is indeed only too easy.
In the classification of the revenue in English budgets and in official returns these charges are deliberately separated from the above sources of the revenue described as taxes, and classed with "revenue derived from other sources."
In 1862 he published a memoir, Intorno alle strie degli spettri stellari, which indicated the feasibility of a physical classification of the stars; and on the 5th of August 1864 discovered the gaseous composition of comets by submitting to prismatic analysis the light of one then visible.
The structure and classification of polyps, however, were at that time very imperfectly understood, and it was fully a century before the true anatomical characters and systematic position of corals were placed on a secure basis.
A collection in which the texts are simply reproduced in their chronological order is obviously inconvenient; towards 550, Johannes Scholasticus, patriarch of Constantinople, drew up a methodical classification of them under fifty heads.
The first contains an explanation of the doctrine of fluxions, and of its application to the quadrature of curves; the second, a classification of seventy-two curves of the third order, with an account of their properties.
See Chemistry for an account of their classification, &c.
For a general account of the structure, development and relationships of insects, see Arthropoda and Hexapoda, while details of the form, habits and classification of insects will be found in articles on the various orders or groups of orders (Aptera, Coleoptera, Dipteria,Hemiptera,Hymenoptera,Lepidoptera,Neuroptera, Orthoptera, Thysanoptera), and in special articles on the more familiar divisions (ANT, BEE, Dragon-Fly, Earwig, &c.).
The number of these principles, their enumeration reason and classification, is an important point, but it is secondary to that of the recognition of their true nature.
Dupuy's classification is still regarded with respect, but the inventory has been partially replaced by the publication of the Layettes du tresor (four volumes, coming down to 1270; 1863-1902).
Indeed, the time was not ripe for such discussions, still less for the tracing of lines of descent and their embodiment in a genealogical classification.
The vast mass of material made known by these and many other distinguished writers has to be included in our classification, and that classification itself must be controlled by the story it reveals.
The barriers between these groups may be regarded as horizontal planes cutting across the branches of the ascending tree of life at levels determined chiefly by our ignorance; as knowledge increases, and as the conception of a genealogical classification gains acceptance, they are being replaced by vertical partitions which separate branch from branch.
The changes may be appreciated by comparing the systematic synopses at the end of this article with the classification adopted in 1877 in the 9th edition of the Ency.
Work has been and is being done by the laborious methods here alluded to, and though the diversity of opinion as to the broader groupings of classification is still restricted only by the number of writers, we can point to an ever-increasing body of assured knowledge on which all are agreed.
Jaekel (1894) has divided the crinoids into the orders Cladocrinoidea and Pentacrinoidea, the former being the Camerata of Wachsmuth and Springer (Monocyclica Camerata, Adunata and Dicyclica Camerata of the present classification), and the latter comprising all the rest, in which the arms are either free or only loosely incorporated in the dorsal cup. In minor points there is fair agreement between the American, German and British authors.
No existing classification of the Asterida is satisfactory even for the recent forms, still less when the older fossils are considered.
There is as yet no satisfactory classification of the Ophiurida into orders expressing lines of descent; even as regards families, leading writers are at variance.
These 19th-century products require some sort of classification for purposes of reference, and the chronological is the most convenient.
Every curve thus arbitrarily defined has its own properties; and there was not any principle of classification.