98 THE ANIMAL PARASITES OF MAN 



Ruminants are said to be refractory to this trypanosome. 



T. equiperdum is about 25 p to 28 //, in length on an average, but 

 varies from 16 //, to 35 p. Its cytoplasm is relatively clear, and does not 

 show chromatic granules (fig. 43). It is stated to be monomorphic. 



It has been shown recently by Blacklock and Yorke (1913) x that 

 there is another trypanosome giving rise to dourine in horses. This 

 trypanosome is dimorphic (resembling T. pecandi and T. ugandcz), 

 and is named T. equi. Previously T. equiperdum and T. equi had 

 been confused. 



Uhlenhuth, Hiibner and Worthe have demonstrated the presence 

 of endotoxins in T. equiperdum. These endotoxins may be set free 

 by trypanolysis. 



Trypanosoma theileri, Bruce, 1902. 



This parasite, 60 JJL to 70 //, long, and 4 p to 5 p broad, is dis- 

 tinguished for its large size, though it is not so large as T. ingens 

 from Uganda oxen, whose length may be 72 //, to 122 //,, and breadth 



7 /A to 10 fju. The posterior 

 end of T. theileri is drawn 

 out. Small forms of the flag- 

 ellate are known, 25 yu, to 53 p 

 in length. Probably other 

 forms of the parasite have the 

 nucleus posterior, and these 



FIG " 200a flagellates were formerly sep- 



arated as T. trausvaalieme 

 (Laveran, 1902). Myoneme fibrils may be seen on its body. The 

 pathogenicity of this organism is doubtful, it was formerly thought 

 to be the causal agent of " gall-sickness " in cattle in South Africa. 

 J. theileri also occurs in Togoland, German East Africa, and Trans- 

 caucasia. Allied or identical parasites occur in cattle in India. 



Trypanosoma theileri, specific to cattle, is perhaps transmitted by 

 the fly Hippobosca rufipes in South Africa. 



Trypanosoma hippicum, Darling, 1910. 



Trypanosoma hippicum causes the disease of mules known as 

 "murrina." 2 It was found in mules imported to Panama from the 

 United States. It can live in other equines. The parasite varies from 

 18 fi to 28 fj, in length, and is from 1*5 p to 3 //, broad. Its undu- 

 lating membrane is little folded. The trypanosome has a noticeable 

 blepharoplast. It can penetrate mucous membranes, and it is thought 

 that the trypanosome may be transmitted during coitus. It may also 



1 Proc. Roy. Soc., B, Ixxxvii, p. 89. 2 Bull. Soc. Path. Exot., iii, p. 381. 



