286 SUGGESTIONS FOE FUTURE WORK. 



obtained from animals suffering from, or which had lately 

 succumbed to, Surra" (pp. 67-68). 



After this extract from Lingard, Col. Bruce observes : — 

 " Up to the present then the results of experiments with 

 serum have been negative, but I purpose if time permits to 

 continue this line of investigation. 



*' Another important point we are still ignorant of is whether 

 animals can become affected by this disease without the agency 

 of the Tsetse-fly or by eating raw flesh, as, for example, by 

 drinking contaminated water or eating soiled herbage. This 

 point I am engaged in investigating. And, lastly, up to the 

 present we do not know of any drug which will prevent the 

 disease or cure it in every instance when incurred " (p. 68.) 



The author concludes with the following " suggestions " as to 

 the lines on which future work in connection with Tsetse- fly 

 disease should be conducted : — - 



" 1. That all trustworthy information regarding seasonal 

 prevalence be collected. 



* If ^ * * 



" According to the ' Natal Almanack,' the dry season includes 

 the months of April, May, June, July and August; the wet 

 season September, October, November, December, January, 

 February and March. As far as I am aware, Nagana is not 

 confined to certain months of the year as Surra is, but I should 

 like to have more definite information on this point. 



" 2. Towai'ds the end of the dry season or when the water 

 pools are nearly dried up, can the Trypanosoma be discovered in 

 this concentrated water by the microscope or by feeding or 

 injection experiments ? 



" 3. The question of herbage. — Dr. Lingard states that in 

 India after the rains have commenced the resting forms of the 

 organism which have been clinging to the grass bordering upon 

 the water-holes begin to soften, and when the animals feed on 

 such vegetation, repeated doses of the contagium are taken into 

 the stomach. It is probable that the small discs gradually gain 

 an entrance into the blood stream and their development takes 

 place in the liver, spleen, and glands generally. All grass-eating 

 animals, therefore, may be the subjects of Surra, so that the 

 opinions held with regard to the big game by the natives are 

 possibly founded on fact. 



" In Africa we are, as yet, in dense ignorance respecting the 

 resting-stage of the Fly hjematozoon ; this would be a most 

 important point to work up. In regard to the herbage, will 

 such grass and water brought up from the Fly Country give 

 rise to the disease in healthy animals kept in a healthy locality ? 



"4. It would be important to find out as far as possible what 

 species of wild animals, vultures, barbel, etc., harbour the parasites. 



