334 



BACILLI PATHOGENIC IN ANIMALS. 



strated in small numbers in the blood of the heart. A 

 rabbit showed after inoculation on the ear erysipelatous 

 swelling, followed by profuse diarrhoea, and death occurred 

 eight days after inoculation. On post-mortem examina- 

 tion catarrh of the intestinal mucous membrane was the 

 only abnormal condition found. Further experiments on 

 animals with this bacillus are desirable. 



Bacterium coli commune (Escherich). 



Microscopical 

 characters. 



These bacilli were obtained by Escherich* from the 

 faeces of children nourished exclusively with their 

 mothers' milk. They are short, slightly curved rods, 

 their length varying from 1 to 5 /*., and their breadth 

 from *3 to '4 /*. They stain intensely with aniline 

 colours, but do not retain the stain when Gram's method 

 is employed. When examined in drop cultivations they 

 Cultivations, show slight mobility. On nutrient jelly the deeply 

 seated colonies present the form of yellow granular 

 discs ; the superficial ones show a white lateral extension 

 with a homogeneous granular appearance, or star- 

 shaped and wrinkled. On agar and blood serum they 

 grow in the form of white deposits ; on potatoes they 

 form a soft layer of the colour of maize or yellow peas. 

 The bacilli slowly coagulate milk with the formation of 

 acid ; in solutions of grape sugar they set up fermenta- 

 tion. When a piece of a cultivation on potato about the 

 size of a lentil is mixed with sterilised water, and injected 

 into the veins of the neck of rabbits and guinea-pigs, 

 the animals die after a few hours, or at latest after three 

 days, with symptoms of elevation of temperature and 

 violent diarrhoea. On post-mortem examination the 

 duodenum and the upper coils of the small intestine 

 show a rose-coloured hypersemia, while the caecum and 

 colon have usually a normal appearance ; Peyer's patches 

 show alterations similar to those seen in the early stage 

 of typhoid fever. In some cases we also find injection 

 of the peritoneum and exudation into the peritoneal 

 cavity. Subcutaneous injection of larger doses produce 

 the same effect in guinea-pigs. 



* FortscJtritle der Medicin.^ vol. iii., 18S5, IsTr. 16. 



Experiments 

 on animals. 



