"I have formulated my view in the following manner: in senile atrophy, 

 we always encounter one and the same picture, namely, an atrophy of the noble 

 and specific elements of the tissues and their replacement by hypertrophied 

 connective tissue. The nerve cells in the brain, i.e., those that serve for the 

 highest forms of activity — mental and sensory functions and the guiding of 

 movements, etc. — disappear and yield their place to lower elements known as 

 neuroglia, a kind of connective tissue of the nerve centers. In the liver, con- 

 nective tissue supplants the hepatic cells that play an important part in the feed- 

 ing of the organism. This same tissue also invades the kidneys; it constricts the 

 canals that are necessary to rid us of a multiplicity of harmful substances. In 

 the ovaries and testes, the specific elements that serve for the multiplication of 

 the species are similarly supplanted and replaced by cells of the granular layer 

 from the connective-tissue series. 



"In other words, old age is characterized by a struggle between the noble 

 elements of the organism and the simple primary ones, a struggle that terminates 

 in favor of the latter. Their victory is reflected in a weakening of mental 

 powers, nutritional disturbances, impaired metabolism, and so forth. 



"When I speak of a 'struggle,' I am not using a metaphor. We are con- 

 cerned here with a veritable battle in the very depths of our bodies." 



Mechnikov ascribed considerable importance in aging to the destruction 

 of the brain cells by macrophages: "... in senile degeneration, an especially 

 important role is played by the atrophy of the nerve cells with the aid of the 

 macrophages." 



In the fight against premature aging, Mechnikov recommends orthobiosis, 

 i.e., the doctrine of the healthy and hard-working life without excesses. Also an 

 important factor in the fight against premature aging, according to him, is the 

 suppression of putrefactive processes in the large intestine by the use of lactic- 

 acid bacteria (he recommended kefir, kumys, and acidophillin) : "In order to 

 render old age actually physiological, it is necessary to counteract the discom- 

 forts resulting from the development of the large intestine." "... thus, it is 

 entirely clear that for the purpose of shortening these slow poisonings, which 

 weaken the resistance of our noble elements and strengthen the phagocytes, we 

 should introduce kefir, and even better, sour milk, into our dietary regimen." 



Mechnikov believed that a third way to fight for a longer life was to sup- 

 press the macrophages by increasing the amounts of specific antimacrophagic 

 immune serum. Mechnikov did not succeed in working out this control method 

 successfully. 



Mechnikov's ideas formed the basis for the investigations of a number of 

 his pupils and successors. These ideas found a certain echo and further develop- 

 ment in each of the great investigators in the field of longevity. 



The works of I. I. Mechnikov laid the basis for the contemporary Soviet 

 science of aging and death, and contributed to the fight for longevity. From 

 that time on, research in this field was widespread in Russia. The first formation 

 of almost all branches of the physiology, biochemistry, and morphology dates 

 back to the 80's and 90's of the last century. 



