THE BACTERIA OF THE NORMAL HUMAN BODY. I45 



coli communis, however, occurs invariably in health not only 

 in the intestine of man, but also in that of many animals, espe- 

 cially in the lower part.* The pyogenic micrococci very often 

 occur in the intestine. 



In the case of ruminant animals like the cow and sheep, 

 the decomposition of cellulose, which forms so large a part of 

 their food, appears to be affected by bacteria. Bacteria having 

 this power are constantly found in the stomachs of ruminants. 

 The best known species is that called bacillus amylobacter. It 

 is questionable whether the products of the decomposition of 

 cellulose have any nutritive value. 



Pasteur some years ago expressed the opinion that if animals could be 

 placed in such surroundings that bacteria could be excluded from the alimen- 

 tary canal and th'e food, life would be impossible. This view has excited much 

 controversy, and was apparently disproved by the experiments of Nuttall and 

 Thierfelder. These investigators succeeded in removing guinea-pigs from 

 the mother by Cesarean section, and in keeping them aHve in sterile surround- 

 ings, upon sterile food, so that the contents of the ahmentary canal remained 

 sterile. Schottelius, who worked with chickens, obtained contrary results, how- 

 ever; so that this interesting question is still undecided. 



* Moore and Wright. Bacillus coli communis from Certain Species of Domes- 

 ticated Animals. American Medicine. March, 1902. 



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