308 



Dr. H. L. Duke. Antelope as a [Apr. 20, 



The following Experiment 195 represents an attempt to influence the 

 course of an infection of T. gambiense in a monkey by treating the latter 

 ■with the serum of Bushbuck 2328. 



Monkey 195 received injections of the serum of Bushbuck 2328 on four 

 occasions as follows : — 



On July 12, 1911, monkey received 15 Tr\ serum subcutaneously. 



No symptoms of serum-anaphylaxis were observed. 



On August 16 to 17, 1911, the monkey was fed upon by positive Experi- 

 ment 22. On August 30, T. gambiense first appeared in the blood of the 

 monkey, the incubation period being thus 13 to 14 days. 



On September 3, 1911, the monkey received '2\ c.c. serum of Bush- 

 buck 2328, without any diminution being observed in the number of 

 trypanosomes. 



February, 1912, Monkey 195 is still alive and apparently in good health. 

 The interval, however, is not long enough to warrant any criticism as to the 

 effect of the above treatment on the disease, which would, however, appear to 

 be pursuing quite an ordinary course. 



The most striking point about this experiment is the long incubation 

 period of the disease in the monkey. Normally after infection with Box 22, 

 trypanosomes appeared in the monkey's blood after an interval of seven days 

 only. Further experiments with this bushbuck had to be discontinued 

 owing to the animal becoming pregnant. 



This bushbuck has apparently successfully resisted the attempt to re-infect 

 it with positive flies in June, 1911. Further investigations are essential before 

 a definite opinion can be pronounced as to its immunity. Experiments will 

 be carried out with a view to re-infection by direct blood injection, and 

 following a negative result, the reaction of the serum will be investigated. 



The following experiments were undertaken to ascertain whether the 

 serum of these antelope had acquired any immunising properties. 



The animal selected was Reedbuck 2359, which at the time, June, 1911, 

 had shown no evidence of infeetivity for some seven months. As may be 

 seen above, this animal was subsequently proved to be infective in July, 

 1911 — one month after the experiments were carried out. 



(1) Has the serum of Reedbuck 2359 any trypanolytic action on 

 T. gambiense ? 



22, 



On August 2, 



15, 



30 



