iv DIGESTION IN THE INTESTINE 225 



It is a fact that it does not exhibit more rapid development and 

 greater vitality than other microbes, since in faeces exposed to the 

 air, in dead bodies, and in putrid matter in general, it gradually 

 diminishes and disappears, and succumbs in the fight with B. 

 pyogenes, B. liquefaciens, Vibrio rugula, and others (Dallemagne, 

 Bordas, Gilber, De Dominicis). 



Fermi also excludes the hypothesis that the almost absolute 

 supremacy of B. coli in the intestine depends on the reaction of 

 the intestinal contents on the bile, on the enzymes of the 

 secretions, or the excreta separated by the mucous membrane 

 acting as an excretory organ, which might favour the development 

 of B. coli, and impede the development of other species. He 

 proved, indeed, that the proteolytic enzymes and bile exert no 

 action on microbes in general, and that many kinds of bacteria 

 flourish luxuriantly in the intestine post mortem, or on its 

 previously sterilised contents. He concludes that there must be 

 a reciprocal adaptation between the epithelia of the normal mucous 

 membrane and B. coli, a kind of symbiosis, while there is between 

 these epithelia and the other species of bacteria (even such as 

 develop more rapidly, and have a greater capacity for resistance 

 and higher fermentation power) a kind of antagonism which 

 obstructs their germination. Fermi finds confirmation of this 

 hypothesis in the fact that when the intestinal mucous membrane 

 is injured by different means, which cannot in any way affect the 

 intestinal bacteria, the latter are profoundly modified, B. coli being 

 reduced, with an invasion of numerous Vibrios, Protozoa, etc. 

 After peritoneal injections of typhoid toxin, Vibrios and also 

 Amoebae appear in the intestine of the guinea-pig, while B. coli is 

 reduced in number and its virulence increases (Sanarelli). When 

 venous stasis is artificially produced in the intestinal walls, the 

 virulence of B. coli increases in the injured loop (Klecki). The 

 same thing occurs in profound lesions of the mucous membrane 

 caused by cholera or dysenteric infections (Dreyfus, Lesage and 

 Macaigne, Jensen). 



These and other similar facts demonstrate the adaptable 

 character or variable attributes of B. coli, which facilitate the 

 interpretation of certain physiological data that must now be 

 considered. 



From our point of view the most important question is 

 whether the fermentative and putrefactive processes normally 

 effected by the intestinal microbes in the food-stuffs modified by 

 the digestive secretions, are or are not to be considered as a 

 second or complementary digestion, useful to the body inasmuch as it 

 completes the chemical work of the enzymes and utilises a greater 

 or less amount of alimentary material which would otherwise 

 be lost with the foetal dejecta. 



The chemical processes which the microbes set up in the 



VOL. II Q 



