686 EPIDEMIC POLIOMYELITIS 



and Noguchi succeeded in cultivating minute bodies which there 

 is reason to suppose are the infective agent. In their experi- 

 ments, small portions of the central nervous system, — preferably 

 the brain, — removed post mortem, were inserted in a medium 

 composed of naturally sterile ascitic fluid containing a fragment 

 of sterile fresh rabbit kidney, and the cultures incubated at 

 37° C. under anaerobic conditions. About the fifth day faint 

 opalescence appeared, and the fluid was found, when treated 

 with the Giemsa stain, to contain minute bluish or violet 

 globoid bodies, about - 2 /* in diameter, in pairs, chains, or, 

 less commonly, in groups. Towards Gram's stain their 

 behaviour was variable. It was found that similar cultures 

 could be raised from the infective filtrates. Further,! the 

 organism could adapt itself to other media and could be 

 maintained in subculture. By inoculating monkeys with these 

 cultures, under precautions which excluded the possibility of 

 infections being derived from the brain matter originally used, 

 poliomyelitis was set up in the animals, and the organism was " 

 recovered from their brains. The " globoid bodies " (whose 

 nature is unknown) were also microscopically demonstrated, by 

 means of the Giemsa stain, 1 in the brain in both the natural 

 and experimental disease. 



In infecting monkeys from a human case it is advisable to 

 commence with the use of an emulsion of the central nervous 

 system, for filtered emulsions possess much less virulence ; but 

 after a few passages through monkeys it is found that filtra- 

 tion has little effect in diminishing the number of successful 

 inoculations, the virus being now so potent that O'OOl to O'Ol c.c. 

 of an emulsion of material from the central nervous system 

 (p. 690) in distilled water will originate the disease when injected 

 into the brain. Such a virus withstands glycerination for years 

 and can be kept frozen at - 2° to — 4° C. without being affected. 

 It also withstands from 1 to 1J per cent, phenol for at least 

 five days ; it is, however, killed by an exposure at 45° to 

 50° C. for half an hour. The disease' can be originated by 

 subdural and intracerebral injection, and also by introduction 

 into the sheath of such a nerve as the sciatic. When the sheath 

 of a nerve is infected, the paralytic symptoms usually first 

 appear in relation to that part of the cord from which the nerve 

 emerges. Infection can also readily be produced by scarifying 

 the mucous membrane of the nose and rubbing the virus into it, 

 or even by simply injecting it into the nasal cavities. The 

 intraperitoneal, intrathecal, and subcutaneous routes can also 

 1 See Flexner and Noguehi, Journ. Exp. Med. (1913), xviii. p. 461. 



