THE EVOLUTION OF DEATH 75 



important, for they refer for the most part to structures whose 

 physiological significance we do not know. It is venturing 

 much to conclude from our ignorance that a disharmony 

 exists. To one physiological disharmony, which he be- 

 lieves he has discovered, our author attributes the very 

 greatest importance. He is of the opinion that our large 

 intestine is too large, and that there occur in it fermentations 

 which produce toxic substances which then act to poison the 

 body. He believes further that these unfavorable conditions 

 become very serious in man with increasing age, and he 

 attributes especially to them the difficulties of the very old. 

 In order to avoid these weaknesses he recommends a treatment 

 which, according to him, is adapted to the suppression of the 

 fermentations in the large intestine. The treatment is 

 simple, for it consists in drinking sour milk. According to his 

 theory the germs pass with the milk into the intestine, where 

 they inhibit the toxic fermentations. It has become in the 

 highest degree improbable that the fermentations in the 

 large intestine have the significance ascribed to them by 

 Metschnikoff, but even if he is right his discovery brings no 

 explanation of senility, as indeed senescence is a very wide- 

 spread phenomenon and occurs also in animals and plants 

 which have no large intestine. 



With how little seriousness Metschnikoff has fomulated 

 his theory will be clear to anyone who reads an article by 

 the American physiologist, C. A. Herter. 34 Herter, whose 

 early death means a heavy loss for science, showed that we 

 have as yet no proof that sour milk has any influence whatever 

 on the bacterial flora of the large intestine, and also no proof 

 that such an influence would be rather beneficial than injurious 

 to man. The problem of intestinal fermentations is ex- 

 ceedingly complicated. 



