SUMMER DIARRHCEA 351 



suspected to contain the bacillus is placed in 15 to 20 c.c. of sterile 

 milk, which is then heated for ten minutes at 80 C. to destroy all 

 vegetative bacteria ; the tube is cooled, placed under anaerobic con- 

 ditions, and incubated at 37 C. for from twenty-four to thirty-six hours. 

 If the bacillus be present there is abundant gas formation, and almost 

 complete separation of the curd from the whey takes place. The former 

 adheres to the sides of the tube in shreds, and large masses gather with 

 the cream on the top of the fluid, all being torn by the gas evolved. 

 The whey is only slightly turbid and contains numerous bacilli. The 

 growth has an odour of butyric acid. If a small quantity (say 1 c.c.) of 

 the whey be injected into a guinea-pig, the animal becomes ill in a few 

 hours and dies in twenty-four hours. At the point of inoculation the 

 skin and subcutaneous tissues, and sometimes even the subjacent muscles, 

 are green and gangrenous and evil-smelling, there is considerable oedema, 

 and there may also be gas formation. The exudation is crowded with 

 bacilli, which, however, are not generally distributed in any numbers 

 throughout the body. These pathogenic properties of the bacillus 

 enteritidis sporogenes are important in its recognition, for its culture 

 reactions taken alone are very similar to those of the bacillus butyricus 

 of Botkin. 



SUMMER DIARRHCEA. 



As has been already stated, both the bacillus of dysentery, b. coli 

 and the b. enteritidis sporogenes have been found associated with 

 epidemics of this disease. This indicates that the condition may 

 be originated by a variety of organisms, and it is further probable 

 that the clinical features in different epidemics vary. The 

 multiple origin of the disease has been illustrated by the work 

 of Morgan, who, in a careful investigation of the disease in 

 Britain, has been unable to find evidence of the dysentery 

 bacillus being present. He has, however, very constantly found 

 in the stools and intestine a bacillus (" Morgan's No. 1 bacillus") 

 which is a motile Gram-negative organism producing acid and 

 slight gas formation in glucose, Isevulose, and galactose, and no 

 change in mannite, dulcite, maltose, dextrin, cane sugar, lactose, 

 inulin, amygdalin, salicin, arabinose, raffinose, sorbite, or ery- 

 thrite ; it further causes indol formation, and in litmus milk 

 slowly originates an alkaline reaction. It produces diarrhoea and 

 death in young rabbits, rats, and monkeys when these animals 

 are fed on cultures. It is thus possible that in this bacillus 

 we have still another cause of the disease. 



