Ti'ypanosome Diseases of Domestic Animals in Uganda. 469 



The commonest trypanosome disease among cattle in Uganda is caused by 

 a trypanosome of the dirnorphon type, which it is proposed to call 

 Trypanosoma pecor urn. This species is probably the same as that which has 

 been known by the name Trypanosoma dirnorphon (Dutton and Todd), and is 

 either identical with, or very similar to, Broden's Trypanosoma conrjolense. 

 The name dirnorphon is a misleading one, and can only be accounted for by 

 Dutton and Todd describing under one name two species of trypanosomes 

 occurring in the same animal. No one, so far as we are aware, has 

 re-discovered Dutton and Todd's Trypanosoma dirnorphon, although many 

 attempts to reconcile later observations with theirs have been made. 

 Certainly the strain kept at the Liverpool School of Tropical Medicine under 

 that name does not agree with the original description. The term 

 T rypanosoma dirnorphon must therefore disappear, since it was born of a 

 misapprehension. But it will at once be said, if the name Trypanosoma 

 dirnorphon must go, why not call the species Trypanosoma congolense ? The 

 only reasons that can be given are, that Trypanosoma congolense is a local 

 name and, therefore, not very suitable, and secondly, that if it comes to strict- 

 priority, then Trypanosoma dimorphon holds the field in spite of its mis- 

 leading character and the error its authors fell into, beca\ise it cannot be 

 denied that there is a strong feeling that Trypanosoma dimorphon and 

 Trypanosoma congolense are one. At the same time it must also be granted 

 that there are others who are strongly of opinion that Trypanosomcc 

 dimorphon and Trypanosoma congolense are distinct species. Under these 

 circumstances it seems best to unite the old names under a new one, and 

 Trypanosoma pccorum seems appropriate enough, as this trypanosome disease 

 is peculiarly one of herds. Montgomery and Kinghorn have lately proposed 

 the name confitsum, in order to get out of the difficulty ; but this name has 

 been used for a trypanosome already, and it is, moreover, an awkward term. 



It must then be understood that in the species Trypanosoma pccorum we 

 include Trypanosoma dimorphon, Trypanosoma conrjolense, the trypanosome 

 discovered in Zanzibar by Edington and described in the ' Proceedings,'* 

 that from Portuguese East Africa and Zululand described by Theiler, and the 

 species found in Northern Ehodesia by Montgomery and Kinghorn, and in 

 Southern Ehodesia by Bevan. 



The other species of trypanosomes found in the blood of cattle in Uganda 

 were Trypanosoma gamhiense, Trypanosoma hrucei, Trypanosoma vivax, 

 Trypanosoma cazalboui, and Trypanosoma nanum. These names, however, 

 may require to be reconsideied. 



* B, vol. 81, p. 14. 



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