TSETSE AND TKYPAXOSOME. 2G5 



appears to be of the opinion that wild animals are also 

 susceptible to Surra." * 



Notes on the habits of the Tsetse, and on the Belatiotts 

 hettoeen it and the Tkypanosoma (p. 150). 



[Translation.] " So far as I am aware, not many 

 observations upon the bionomics of the Tsetse exist. The 

 fly appears to live in reed-beds bordering streams, and in 

 damp bush. It flies at its victim with a buzzing noise, 

 bites it in the flanks, on the belly, and elsewhere, and, 

 according to an observation by Veterinary-Surgeon 

 Schmidt, disappears again with equal rapidity. It is 

 said not to pursue its victim. The fly bites only during 

 the day, or, at most, on bright moonlight nights in 

 addition. Consequently in most cases Tsetse-districts can 

 be passed through with animals without harm in the 

 night. 



"The mode of development of the Tsetse is still, so 

 far as I am aware, entirely unknown.f A yet richer field 

 for research, however, is ofiered by the investigation of 

 the development and life-history of the blood-parasite 

 (Trypanosoma), which is the actual cause of Surra disease. 

 Probably, just as the plasmodium of malaria does in 

 Anopheles, the parasite passes through a special generation 

 in the body of the fly. Undoubtedly, just as in the case 

 of malaria, it is possible for one ox to be directly infected 

 with Surra from another by means of inoculation of 

 blood ; but the normal course of development will be, as 

 in malaria and Texas fever, that in the biting insects 

 the Trypanosomes pass through a special developmental 

 cycle (sexual reproduction). In malaria, according to 

 the investigations of Ross and Grassi, the parasites 

 (Plasmodium) pass into the stomach, thence into the 

 stomach-wall, and finally into the salivary glands." 



On pp. 151-152 a diagnosis of the genus Trypanosoma 

 is given, derived from Biitschli's article on Protozoa in 

 Bronn's " Klassen und Ordnungen des Tierreichs." On 



* In other words, if Schmidt's view is correct, the parasite of Tsetse- 

 fly disease will only exceptionally be found in the blood of an antelope, 

 buffalo, or zebra ; since its presence in the blood would entail the death of 

 a wild animal equally with that of a domesticated one. This, however, is 

 contrary to the experience of other observers. — E. E. A. 



t Dr. Stuhlmann is evidently ignorant of Col. Bruce's discovery on 

 this point. — E. E. A. 



