Caused by the trypanosome parasite Trypanosoma brucei rhodesiense, which is carried by the tsetse fly, the disease is fatal if not treated.
Dutton, who (11) gave this form the name of Trypanosoma gambiense.
Nevertheless the resemblance between the biology of this organism in relation to syphilis (as regards mode of infection, habitat, &c.) and that of Trypanosoma equiperdum, the cause of dourine or " horse-syphilis," may not be without significance.
One of the most serious diseases to these animals is trypanosomiasis caused by Trypanosoma evansi.
Plimmer, " The Trypanosoma brucei, the organism found in Nagana or the Tsetsefly disease," Quart.
Schaudinn has stated, however, that Trypanomorpha becomes, in certain phases, attached to a red blood-corpuscle (ectoglobular), and, in others, penetrates inside one and eventually destroys it (endoglobular); while his other avian parasite, Trypanosoma ziemanni, apparently draws up into itself the white corpuscle (leucocyte) to which it becomes attached.
Siedlecki have published an important account (17) of this parasite, which they consider possesses a true trypaniform phase, and for which they have proposed the name Trypanosoma luis.
That one and the same species may appear entirely different in different phases of the life-history is manifest on comparing, for instance, the chief " forms " of Trypanosoma FIG.
The end by which the parasites join is typically, in the case of Trypanosoma, the non-flagellate (anterior) end.
The generic name of Trypanosoma was conferred by Gruby in 1843 upon the wellknown parasite of frogs.
The genus Trypanosoma, in which are included at present the great majority of Trypanosomes, is rather to be regarded as derived from a Heteromastigine ancestor, such as Trypanoplasma, by the loss of the anterior flagellum.
Until lately it remained quite uncertain, however, whether the invertebrate merely conveys the Trypanosomes or whether 1 Trypanosoma equiperdum, the cause of dourine in horses and asses, is apparently only conveyed by the act of coitus.