EXPERIMENTAL INOCULATION 349 



In the lower animals, with the probable exception of the monkey, the inocu- 

 lation of leprous tissues or cultures of the organism produces no result [but vide 

 infra]. 



In the lesions found by Melcher and Orthmann, and Tedeschi, after the inocula- 

 tion of a rabbit with pieces of leprous tissue, the presence of what was probably the 

 tubercle bacillus as well as other organisms unconnected with leprosy was demon- 

 strated. Thiroux, in Madagascar, inoculated four rabbits with leprous nodules : 

 all four animals developed typical and fatal tuberculosis ; the tissues were sown 

 and yielded cultures of the tubercle bacillus. Numerous inoculation experiments 

 carried out on monkeys (Babes), pigs (Hilairet and Gaucher, Widal), dogs (Neisser, 

 Danisch), rabbits (Wesener), and cold-blooded vertebrata (Kobner), and more 

 recently the experiments of Besnier and Leloir, have all failed to give rise to leprosy 

 in the inoculated animal. 



A piece of leprous tissue inoculated beneath the skin of an animal retains its normal 

 appearance for a long time, and the bacilli contained in it will stain even after the 

 lapse of several months, but they never undergo any multiplication. The tissue 

 is gradually absorbed by leucocytes which congregate around it. 



C. Nicolle has succeeded in inoculating macacus monkeys with leprosy. 



A non-ulcerated leprous nodule was pounded in a mortar and inoculated into the 

 ear of a bonnet monkey (Macacus sinensis) : sixty-two days later leprous nodules 

 containing quite typical leprosy bacilli were found to have developed. Six other 

 macacus monkeys (Macacus sinensis and Macacus rhesus) are said to have been 

 successfully inoculated beneath the skin : by repeating the inoculations the suscepti- 

 bility of the monkey is increased and the period of incubation can be reduced from 

 two months to a fortnight (fourth inoculation). The lesions resolved spontaneously 

 in 29-160 days. For purposes of inoculation, material rich in bacilli from untreated 

 lesions should be used. 



[Host also successfully infected a monkey by repeatedly inoculating it with 

 an organism which he had cultivated from a case of leprosy. The monkey 

 exhibited all the clinical features of tuberculous leprosy and in the nodules 

 acid-fast bacilli were found situated as in leprosy. 



[Host failed in his attempts to infect guinea-pigs, white rats and rabbits 

 either by inoculation (sub-cutaneous and intra-peritoneal) or by feeding. 



[Bayon inoculated rats and mice with an acid-resisting diphtheroid bacillus 

 which he had cultivated from cases of human leprosy and found that the 

 organism when recovered from the organs of these animals had acid-fast 

 properties. This acid-fast organism when inoculated into a further series of 

 rats and mice caused " the identical changes of genuine spontaneous rat 

 leprosy and very striking analoga of the glands and organs of human 

 cases." 



[Williams with his pleomorphic streptothrix (vide infra) produced in 

 guinea-pigs by sub-cutaneous inoculation a lesion somewhat resembling 

 leprosy with large numbers of cocco-bacilli in the cells of the connective 

 tissue. 



[Duval used cultures 2-3 days old on glycerin-blood-agar. By inoculating 

 monkeys (Macacus rhesus) sub-cutaneously two or three times at intervals 

 he was able to produce lesions resembling those of leprosy. The monkeys 

 lost all sensation to pain and the skin for a radius of 2-3 cm. about the nodules 

 was distinctly hypersensitive. About 6-8 weeks after the first inoculation 

 the animals exhibited typical signs of disseminated infection and presented 

 the clinical picture of human leprosy of the tuberculous type.] 



Sugai inoculated an emulsion made by grinding up young lepromata in 

 normal saline solution into Japanese dancing mice, with the result that small 

 granulomata similar to those of miliary tuberculosis appeared on the peri- 

 toneum while the mesenteric and bronchial glands became enlarged. The 

 leprosy bacillus was present in the lesions. 



