26 AGE, GROWTH, AND DEATH 



Now the bodies produced by fermentation, the chem- 

 ical bodies, I mean, get into our system and poison 

 us. The result of the poisoning is that the native 

 capacities of the various tissues and organs of the 

 body are lowered, as happens in a man " intoxicated." l 

 All parts of a man may be poisoned, not necessarily 

 always with alcohol, but with many other things as 

 well, and such a poisoning Professor Metchnikoff 

 assumes to result from intestinal fermentation. More- 

 over, he has further observations, which lead him to 

 the idea that certain cells go to work upon the 

 poisoned parts and do further damage. The cells 

 in question are minute microscopic structures, so 

 small that we cannot at all see them with the naked 

 eye, but which have a habit of feeding in the body 

 upon the various parts thereof whenever they get a 

 chance. Cells of this sort go by the scientific name 

 of phagocytes, which is merely a Greek term for 

 " eating cells." The phagocytes, for instance, devour 

 pigment in the hair, and in old persons the production 



1 The " poison-theory " of old age and death has recently been adopted by 

 Prof. T. H. Montgomery, Jr., who has written : "Perhaps the best substan- 

 tiated view ... is that natural death of the individual results from self- 

 poisoning. The waste products of metabolism, some of them toxic, accumulate 

 in the tissues until there results a true intoxication of the latter. We may try 

 to transcribe this into a little more definite physiological phrase : death follows 

 on account of the insufficiency of the excretion process, therefore the limit of 

 life is a matter of excretion " ( Transactions Texas Academy of Science, ix, 

 pp. 77, 78). The author gives no evidence to justify these assertions, and they 

 are therefore hardly available for discussion. P. 79, Montgomery dissents from 

 my views on differentiation, because I have failed to recognise " the underlying 

 factor of senescence, which is insufficiency of the excretion process." The 

 present volume aims to prove that the underlying factor of senescence is another 

 than that assumed by Montgomery. 



