416 FAMILY: TRYPANOSOMID^ 



With the Indian virus, Row (1912, 1913) was successful in inoculating mice. The 

 virus employed was obtained either from a local cutaneous nodule in a monkey, the 

 spleen of infected monkeys, or cultures of the organism. Maokie (1914, 1915/)) 

 infected mice from material from human cases, and Laveran (1917) was also success- 

 ful. Shortt (19236) produced a heavy infection in a mouse with the Indian virus. 

 Adelheim (1924) produced heavy infections in mice with a virus he obtained from a 

 dog which had been brought to Riga from Tashkent. Subcutaneous injection pro- 

 duced, not only a generalized infection, but also a local sore in which the parasites 

 tended to persist longer than in the internal organs. 



Rats have also been infected with the Mediterranean virus by Laveran (1912c) 

 and Yakimoff and Kohl-Yakimoff (1912rt). Patton (1912a) infected a rat with the 

 Indian virus, while Cornwall and La Frenais (1916) infected one by injection of 

 cultures and another by feeding it on bread soaked in culture. The organisms 

 were only demonstrated in the infected animals by the culture method. The writer 

 (1915c) was also successful in infecting white rats directly from a human case. 



Guinea-pigs were first shown to be susceptible to the Mediterranean virus by 

 Laveran and Pettit (1909/>). Franchini (1911) claimed to have produced a general 

 infection in a young guinea-pig by injection of cultures. With the Indian virus 

 guinea-pigs have not yet been infected. The only general infection in a rabbit was 

 recorded by Mantovani (1912). Volpino (1911) infected the cornea of a rabbit by 

 scarification with material from the spleen of an infected dog. About three months 

 after the cornea showed a lesion which resembled those produced by the virus of 

 syphilis. Numerous leishmania were present in the lesion. Rabbits do not appear 

 to have been infected with the Indian virus. Rabbits and guinea-pigs are evidently 

 difficult to infect, as many failures have been recorded. Cats also have never been 

 infected, though on one occasion a naturally infected kitten was discovered in Algiers. 



With the Sudan virus Archibald (1914) infected the jerboa and the gerbil, while 

 with the Indian virus Mackie (1914) infected the flying fox {Pteropus edwardsi). 



In this connection it is of interest to note that Archibald (1914), working with the 

 Sudan virus, was successful in infecting two monkeys by feeding them with crushed 

 infected spleen of man or experimental monkey. He faUed to infect a young dog 

 by this method. 



As regards infections in animals, it is rarely that leishmania can be foimd in 

 the peripheral blood. Liver puncture can generally be carried out, but parasites 

 are not numerous in this organ. Spleen puncture is difficult to perform, though on 

 one occasion the writer diagnosed a case of infection in a dog by this method in 

 Malta. Bone marrow can be obtained by trephining a rib or one of the long bones 

 of the leg under an anaesthetic. In dogs, at any r.ate, this method gives the most 

 reUable information. Cultures from the blood have also been obtained. 



Dogs and monkeys which have recovered from infections have been shown by 

 NicoUe (1910) and NicoUe and Comte (1910) to be immune to further inoculations. 

 Laveran (1914a) notes that a monkey which had recovered from infection with the 

 Mediterranean virus was immune to inoculation with the Indian one. 



From the foregoing summary it wdl appear that many successful inoculations 

 of animals have been effected. The infections, however, cannot be compared with 

 those produced by pathogenic trypanosomes, for they are nearly always of slow 

 development, and the number of organisms found is generally small. The want of 

 an easily inoculable and susceptible host for L. donovani has been a great obstacle 

 to the carrying out of experimental work on the method of transmission of kala azar. 

 Recently, however, Smyly and Young (1924), and Young, Smyly, and Brown 

 (1924), have shown that in Xorth China the hamster {Cricetulus griseus) is more 

 susceptible than other laboratory animals. Successive passages of a virus were 



