the Domestic Animals in Nyasaland. 



55 



importance, as under natural conditions goats will always be infected by 

 the bite of the " fly " ; but it is interesting as showing the fallacy of judging 

 from the action of laboratory strains as to what will occur in nature. 



Among the goats infected by wild G. morsitans, there are many cases of 

 mixed infection. On referring to Table I it will be seen that there are 

 15 cases of infection by wild 67. morsitans among the goats. Of these, only 

 three were cases of pure infection with T. simice, the remaining 12 were 

 mixed infections. These three died, on an average, in 32 days. There 

 were 12 cases of mixed infection ; of these, one recovered and the remaining 

 11 died, on an average, in 49 days. 



From this it would appear that T. simice, acting alone, is as rapidly fatal to 

 goats as it is when occurring in various combinations with T. hrucei, 

 T. pecorum, or T. caprce. T. simice infection, when the result of the bite 

 of the " fly," must therefore be looked upon as a fairly deadly enemy to 

 goats. 



During life this disease of goats is not marked by any special symptoms. 

 There are neither swellings of the body, limbs, or face, nor corneal 

 opacities, as is sometimes the case in other trypanosome diseases of goats : 

 the animal merely becomes more and more ansemic and emaciated, and 

 finally dies of exhaustion. 



Disease set up in the Domestic Pig by T. simise. — In the whole range of the 

 trypanosome diseases of animals there is surely nothing so striking as the 

 rapidly fatal action of T. simice on the domestic pig. In nine experiments 

 the average duration was only 5"3 days. This, not from the time of the 

 appearance of the trypanosonies in the blood, but from the date of infection. 

 Further, this rapid action is not the result of an exaltation of virulence 

 by numerous passages through the pig, but natural to the trypanosome. 



In regard to the symptoms of the disease during life, nothing noteworthy 

 happens owing to the rapidity of the disease. 



Disease set up in the Monkey by T. simiae — This trypanosome is also remark- 

 ably fatal to the monkey. In 20 experiments with wild 67. morsitans 

 17 monkeys died, the duration, on an average, being only 9 - 5 days from the 

 day the flies were fed. Three are still alive after 318, 159, and 74 days, 

 and have evidently recovered. When a monkey is inoculated with blood from 

 an infected monkey the result is the same, the duration in five cases being 

 106 days. It will be seen, however, from Table I, that these five monkeys 

 were all inoculated with blood from monkeys which had only very recently 

 been infected by the bite of the "fly." On the other hand, when a 

 monkey is inoculated with blood from a goat infected with T. simice, the 

 result, as a rule, is negative. Ten monkeys were inoculated with blood of 



