550 . TRYPANOSOMIASIS 



bird, only trypanosome forms were found to develop in its body. These 

 results are, of course, not quite conclusive, as the halteridium stage 

 might only follow on the sexual portion of the cycle. In this connection, 

 however, the fact may be mentioned that both with Tr. Brucei and Tr. 

 ugandense attempts to produce disease by means of the contents of the 

 stomachs of infected insects have failed. Bruce was of opinion that 

 infection took, place in nagana by means of the insect carrying the 

 trypanosomes in the tube of its proboscis, where he observed them to be 

 freely motile for forty-eight hours after the insect had fed, and with 

 regard to the sleeping sickness organism Minchin held a similar opinion, 

 and showed that if a glossina bit an infected animal, and then in succes- 

 sion two healthy animals, only the first of the latter would contract the 

 disease the proljoscis being apparently cleaned by the biting process. 



Reference may here be made to the views put forward by 

 Schaudinn regarding the relationship of certain spirilla to the 

 trypanosomes. In the athene noctiia, besides the Tr. noctuae 

 already referred to, there is a protozoal parasite infesting the 

 leucocytes known as spirillum Ziemanni or leucocytozoon 

 Ziemanni, whose invertebrate host is also the culex pipiens. 

 Ziemann had described the male and female forms in the owl, 

 and microgametes had been observed forming from the micro- 

 gametocytes. Schaudinn observed the formation of an ookinete 

 in the mosquito ; in certain cases this ookinete elongates, and 

 the vermicule rolls itself up into a ball with great proliferation 

 of the nucleus. Each little nucleus attaches to itself a portion 

 of the protoplasm, and becoming a miniature trypanosome, 

 swarms off and becomes free. These minute trypanosomes 

 elongate and develop into typical spirilla by rolling their ribbon- 

 shaped bodies spirally along their longitudinal axes, the 

 individuals possessing male, female, or indifferent characters, 

 just as in Tr. noctuae. These spirilla multiply by longitudinal 

 division, and often after fission the two individuals remain 

 attached to each other by their posterior ends, and in this way 

 there is made possible what is often seen in spirilla, namely, a 

 capacity to move in either direction. The spirilla often divide 

 so frequently that ultimately the individuals become invisible by 

 means of the microscope and can only be seen when lying in 

 clumps. In this stage Schaudinn thinks the organism would be 

 able to pass through a Chamberland filter, and this may be a 

 very important observation, as throwing light on the etiology of 

 certain diseases, such as yellow fever, in which no visible parasites 

 have been found. 



Schaudinn's views on the trypanosomal characteristics of Sp. Ziemanni 

 have raised important questions regarding the morphology of other 

 similar forms which have been long familiar, such as Sp. Obermeieri, 

 and also of the Spirochsete pallida which Schaudinn himself discovered. 



