TRYPANOSOMIASIS IN THE ANGLO-EGYPTIAN SUDAN 121 



in the luEmatoerit tubes, and carefully examiued both iu the fresh and stained condition, no 

 trypanosoines were found. 



From Ox No. 4. On 23rd November a rabbit received 2 c.c. of blood containing a 

 considerable number of trypanosomes, six to the microscopic field (employing Leitz, obj. 6, 

 oc. 4, without ocular diaphragm), aud a monkey (Cermpifhecm) received 1 c.c. The result 

 in the case of these animals was also negative, though they remained under observation for 

 two months. 



On 4th December a brown pariah dog received 2'5 c.c. of fresh blood subcutaneously 

 at a time when trypanosomes were fairly numerous. 



A black pariah dog received as food large pieces of the liver and spleen aud several of 

 the enlarged glands, all soft food be it noted. 



These experiments also proved absolutely negative. 



On 29th December the last-mentioned rabbit happened to be killed accidentally. A 

 post-mortem was performed immediately, but no trypanosomes were found in the blood or in 

 any of the organs. It would appear, then, that dogs, rabbits, and monkeys {Cercopithecua) 

 are not liable to infection with T. nanum, though it must be confessed that the number of 

 experiments was too small. As it was desired to institute further experiments, the cow from 

 Melut was brought to Khartoum, arriving there on 4th March, 1905, along with her calf. 

 The blood of both animals was examined, but no trypanosomes were present 



The cow, and there was no doubt as to her identity, was in very poor condition and 

 presented all the symptoms of the disease, but repeated centrifuging of considerable quantities 

 of blood failed to reveal the parasites. On 7th March, 1905, 4 c.c. of the cow's fresh blood 

 was inoculated subcutaneously into her calf, but though numerous examinations have been 

 made of the blood of the latter, T. nanuin has nut once been found. Nor has the cow again 

 exhibited trypanosomes up to the time of writing (December, 1905). She was well fed and 

 steadily improved in health and appearance. In this connection one must note that the 

 Uganda experiments indicated that there is no transmission of immunity from a trypanosome 

 infected animal to her offspring and that an apparently recovered animal may months later, 

 as a result of lowered vitality, again exhibit infection [ride Lancet, May 14th, 1904). 



A sample of her milk was analysed by Dr. Beam and yielded the following figures : — 



Total solids 21'5 per cent. 



Fat 11-2 ,, ,, (a very high figure). 



Solids not fat ID'S ,, ,, 



I had neither the time nor the means at my disposal to conduct an extensive series 

 of cattle inoculations, nor was I able to secure other cattle suffering from trypanosomiasis. 



Taken m conjunction with what was found in Ox 3 it would, however, appear that 

 T. nullum is in the habit of disappearing for long periods from the peripheral blood, and j 

 I am strongly inclined to think that spontaneous cui'e may occur. It is possible that, under , 

 favourable conditions, such as removal from an endemic area and plenty of good food / 



ensured, a trypanosomicide is produced in the blood which proves fatal to the parasites. 

 Supposing for a moment that this be the case, it may prove possible to utilise the sera of Possible 

 recovered cattle as a therapeutic agent. I hope yet to be able to exploit this field of research sp°"'aneous 

 which, though already explored to some extent in the case of other trypanosomes, seems 

 Well worth investigating in the case of a new and uudoubtedly somewhat benign form like I 

 2'. ininnm. A proper animal house, however, would be required, and more assistance than is ' 

 at present available, while the undertaking would be somewhat costly, as I have not yet 



