84 MICROBES AND TOXINS 



be too much to say that these figures are imaginary, but they 

 are certainly only approximate. It is sufficient to state that 

 the real figure is enormous and certainly approaches the 

 magnitude stated. 



The small intestine is less populous, so much so that a 

 bactericidal action even has been ascribed to it. Yet the 

 pancreatic juice which is poured into the small intestine is 

 invaded by microbes when collected and left outside the body. 

 The auto-sterilisation of the small intestine seems to be due to 

 the combined action of the two principal digestive juices, the 

 pancreatic and the intestinal. The flora of the small intestine 

 like that of the intestine in general varies with the diet. 



It is more important to know the nature of the microbes 

 than their quantity. In 1898 Mannaberg counted only 

 twenty-seven species in the intestine ; but there are now many 

 more described and the improvement in our methods of 

 cultivation is leading daily to the discovery of new ones. 

 MacFadyean, Nencki and Mme. Sieber have isolated fourteen 

 from the small intestine alone. 



A child is born with a sterile alimentary canal, but from the 

 tenth to the twentieth hour of life it begins to be inhabited. 



Fig. 9. — Bacillus bifidus (Tissier) : Fig. 10. — Bacillus bifidus 



10 day culture. (Tissier) : 15 day culture. 



From the first to the third day in i\\Q breast-fed child there 

 appear Streptococci, Bacillus coli, B. perfringens ( = Welch's 

 Bacillus), B. Ill of Rodella, B. ladis aerogenes, Sarcinae, 



