XVIl] AFRICAN PATHOGENIC TRYPANOSOMES 299 



B. Trypanosomes in which the flagellum does not become 

 free anteriorly. 



/Parasite distinctly dimorphic .. =rf)Jno>'/)/!on, Laveran and Mesnil. 



\ Parasite nionomorphic . . . . . . . . . . . . —7. 



f Monkeys, dogs, rabbits, etc., refractory to infection =nannm, Eaveran. 

 I ^lonkeys and goats susceptible ; dogs, rabbits, etc., refractory to infection 

 J = si mi a-, Bruce, Harvejr, Hamerton, Davey, and Eady Bruce *. 



Monkeys, dogs, rabbits, etc., susceptible to infection 

 _ f congolense, Broden. 

 ^ \pecorum, Bruce, Hamerton, Bateman, and Mackie. 



The latter two species are distinguished by cross immunity reactions. In 

 addition T. pecorum is more virulent than T. congolense. 



C. Trypanosomes having forms with a free flagellum and 

 forms without a free flagellum. 



J" Trypanosomes immobilised by human serum . . =pecaudi, Laveran. 



\Tr\-panosomes unaffected bjr human serum .. .. .. =2 



fin rats, trypanosome shewing a variable proportion of forms with the 

 I troplionucleus at the posterior end of the body 



^ ■{ =rhodesiense, Stephens and Fantham. 



I Trypanosomes never shewing any posterior nuclear forms 

 L =gambiense, Button. 



* In this species the extreme tip of the flagellum may sometimes become 

 free for a length of 2—3 microns. 



REFERENCES. 



Laveran and Mesnil (1912). Trypanosomes et Trypanosomiases, 2nd 

 edition. Masson et Cie. Paris. (Contains a very complete account 

 of the literature on the subject.) 



