508 FAMILY: TEYPANOSOMIDiE 



are not those in which disease is produced, but rather the wild animals of 

 the country, which harbour them without suffering in any serious manner, 

 just as Trypanosoma lewisi occurs in the rat. In other parts of the world, 

 with the exception of South America, where the capibara is said to be the 

 reservoir for T. equinum, the pathogenic trypanosomes, which are of the 

 T. evansi type, appear to be transmitted amongst the domestic animals 

 alone. This is undoubtedly accounted for by the fact that it is only in 

 Africa that domestic animals come into close contact with the game. 

 It is on account of the importance of these trypanosomes from an economic 

 standpoint that they have attracted so much attention. 



In tsetse-fly areas of Africa the domestic animals have been found 

 infected as follows: 



Horse, Mule, and Donkey: T. brucei, T. vivax, T. congolense. 



Ox: T. gamhiense{1), T. brucei, T. vivax, T. congolense, T. uniforme, 

 T. montgoyneryi. 



Pig and Camel: T. brucei, T. congolense. 



Sheep and Goat: T. gambiense (1), T. brucei, T. vivax, T. congolense, 

 T. caprcB. 



Dog: T. gambiense, T. brucei, T. congolense, T. montgomeryi. 



Relation to Game. — In Nyasaland in the fly country below Kasu Hill, 

 the Royal Society's Commission under Bruce (1913e) found that the 

 wild game harboured trypanosomes to the extent of 31-7 per cent. The 

 species found were T. brucei (7-8 per cent.), T. pecorum {T. congolense) 

 (14-4 per cent.), T. simice (1-7 per cent.), T. caprcB (11-1 per cent.), and 

 T. ingens (1-7 per cent.). As regards the wdld tsetse flies {Glossina morsi- 

 tans), of 1,060 examined by Bruce et al. (1914/) T. brucei was found once, 

 T. pecorum six times, T. simice twelve times, and T. caprce fourteen times. 

 Similar results had previously been obtained by Bruce (1895) in Zululand, 

 though at that time all the pathogenic trypanosomes were considered to 

 belong to the species T. brucei. 



Domestic animals living in the area were found infected to a limited 

 extent, but their numbers were so small as to constitute little danger. 

 Of 140 goats examined, five showed T. pecorum and one T. caprce ; and of 

 twenty-two dogs, six harboured T. pecorum and ten T. brucei. 



Kinghorn and Yorke (1912a) found that trypanosomes were of frequent 

 occurrence in the domestic stock of North-East Rhodesia. As regards 

 the big game, a conservative estimate placed the percentage of those 

 infected at about 50 per cent, in the Luangwa Valley, and 35 per cent, in 

 the Zambesi-Congo basin. The trypanosomes found were T. brucei 

 {T. rhodesiense), T. vivax, T. congolense {T. nanum and T. pecorum), 

 T. montgomeryi, T. multiforme {T. brucei or T. gambiense, or a mixed 



