45 



of the identity of the trypanosome of Mauritiiis and mbori, but is inclined 

 to consider trypanosome of mbori as a variety of Trypanosoma evansi. 

 Similar experiments were undertaken by Laveran and Mesnil* to prove 

 that the trypanosomiasis of Nha-trang in Annam was identical with surra, 

 after it was proved that they did not differ either in morphology or in 

 their pathological action. A male goat which was immune against both 

 mbori and surra of Mauritius, and whose blood inoculated into susceptible 

 animals had proved to be sterile, was inoculated with surra from 

 Nha-trang. It contracted the disease and died. 



A goat which had recovered from an infection of a Mauritius 

 strain of surra and had proved to be immune to the test with the virus, and 

 after sub-inoculations into smaller animals had proved that the blood 

 had become sterile, was inoculated with virus of Nha-trang. The animal 

 contracted the disease aM died. Here the immunity of surra and mbori 

 did not protect against a third strain of surra virus of Nha-trang. Laveran 

 and Mesnil's interpretation of these facts is of a close relationship of the 

 two strains, bxit of different variety ; but they do not consider the 

 Nha-trang strain to be an entity of its own. 



Conclusion. 



(1) Cattle which recovered from surra of Mauritius proved immune 



to the test when reinjected with the same virus. 



(2) Goats ivhich recovered from mbori proved immune to the test when 



injected with the same virus. 



(3) Cattle which were immune to surra of Mauritius proved to he 



immune to mbori and to surra of India. 



(4) Goats which were immune to mbori proved to be immune against 



surra of Mauritius. 



(5) Goats immune to surra of Mauritius and mbori, or to surra of 



Mauritius alone, proved not immune to surra of Nha-trang. 



(6) The blood of animals whose immunity was tested proved to be 



sterile. 



Although there are pathogenic differences described by Laveran,! 

 Trypanosoma sudanense, which morphologically cannot be distinguished 

 from Trypanosoma evansi, had to be considered as a specie of its own, 

 owing to the interpretation of the immimity test. Laveran used a goat 

 which had recovered from an infection with Trypanosoma sudanense. 

 After the blood had become sterile and had proved to be immune 

 against a subsequent test it was injected with Trypanosoma evansi of 

 the mbori disease with positive results. 



In the reverse experiment, a goat recovered from nibori, and after 

 the blood had become sterile proved to be immune against this strain, 

 was successfully infected with Trypanosoma sudanense. One virus did 



* Recherches Experiraentales sur la Trypanosomiase des Clievaux cle I'Annam. 

 t Tryp, du Haut Niger Ann. de Tins. Past. t. 21, No. 5. 



