TRYPANOSOMES ALLIED TO T. EVANSI 571 



disease in dromedaries in Italian Somaliland by Martoglio (1911), and in 

 South- West Africa by Reinecke (1911). Tlieiler (19066) met with the 

 same trypanosome in South Africa in dromedaries which had come from 

 Somaliland. 



T. annamense Laveran, 1911. — Another trypanosome morphologically 

 indistinguishable from T. evansi is one first noted by Blanchard (1888) 

 in horses in Tonkin and Annam. It has been studied by various observers, 

 and found to occur also in cattle. Laveran (1911) studied the trypano- 

 some, and found that goats which had acquired an immunity to the true 

 T. evansi of India could still be infected with the Annam strain. Accord- 

 ingly, he designated the trypanosome T. annamense. 



T. soudanense Laveran, 1907. — ^Another disease caused by a trypano- 

 some, and again in the same animals, is the debab of Algeria and Egypt, 

 and probably North Africa generally. It extends into the same districts 

 in which Cazalbou studied the disease mbori. A strain of this trypano- 

 some, which was isolated from a camel, was studied by Laveran (1907) by 

 immunity tests in goats. This led him to regard it as a species distinct 

 from that causing mbori. The trypanosome, which he named T. souda- 

 nense, is not distinguishable from T. evansi save by its immunity reactions. 

 It is possibly this trypanosome or the variety of T. evansi causing mbori 

 which is responsible for the disease of camels in Khordofan and Somaliland. 

 T. berberum Sergent, Ed. and Et., 1904, and T. marocanum Sergent, 

 Lheritier, and Belleval, 1915 — These two trypanosomes of the T. evansi 

 type are also recorded from North Africa. T. berberum produces a disease 

 of camels and horses similar to debab throughout North Africa, while T. 

 marocanum was encountered in an outbreak amongst horses at Casablanca. 

 On the evidence of cross-immunity tests these trypanosomes were stated to 

 differ from one another and also from T. evansi. Sergent, Ed. and Et., and 

 Donatien (1920) have shown that T. berberum may, at the height of an 

 infection, pass through the placenta and bring about infection and death of 

 the young in utero. Camels which have passed the acute stage of the disease 

 bear healthy young, which, however, possess no immunity to infection, 

 Vialatte (1915) and Donatien and Parrot (1922) have reported T. berberum 

 as occurring naturally in dogs, while similar observations for T. marocanum 

 have been made by Delanoe (1920) and Velu (1920). 



A trypanosome of camels in Russian Turkestan was named T. nince 

 I'ohl-yakimov by Yakimoft" (1921a), who claims that it differs from T. evansi 

 in pathogenicity to laboratory animals and serum reactions, tests which 

 are quite insufficient to justify the creation of a new species. 



It will be seen from the above account that these various supposed 

 species produce diseases in those animals which are known to suffer 

 from surra. Moreover, they are morphologically indistinguishable from 



