and the cliangcs in the nervous system are actually the consequences of changes 

 in the cells of the organism, we find that in old age the role of the nervous system 

 becomes the major one, and atrophy from aging is of neurotrophic origin" 

 (M. S. Mil'man). [Tr.: This quotation has an end but no beginning.] 



The significance of Mil'man's work is to be found above all in the accu- 

 mulation of a great deal of anatomical-histological material on the processes of 

 senile atrophy and dystrophy. His theory of aging, although characterized by 

 its consistency, is constructed in an extremely one-sided manner and does not 

 cover the real wealth of the relationships between growth, nutrition, and tissue 

 differentiation in the organism. \Ve can scarcely regard the dimensions of the 

 cells as the factor that limits their nutrition; as a compensation, the protoplasm 

 becomes more penetrable. It is entirely impossible to explain cell and tissue 

 differentiation by nutritional deficiency. The fact that the tissues of higher ani- 

 mals are supplied by the circulatory system with capillaries does not impair but 

 rather improves considerably the supply of oxygen and nutrients to their tissues, 

 and this is indicated by the higher energy metabolism levels of mammals and 

 birds as compared with the lower vertebrates, although their body masses fluc- 

 tuate within narrow limits. Senile changes in the microstructure of nerve 

 tissue are not greater but even smaller than those of many other tissues. 



In view of all of this, we cannot express our agreement with the one-sided 

 theory of the aging of organisms advanced by M. S. Mil'man, although we do 

 commend his extensive research activities. Grasping only the one aspect of 

 growth to which his simplified concept applied, Mil'man saw the growth and 

 development of organisms only as regressive (bioreductive) processes. The 

 phenomena of biological progress do not fit into Mil'man's concept at all. 



During the Twenties, in addition to the echoes of A. Steinach's and S. 

 VoronofPs hormonal theories of aging (1920 and 1921, respectively) that spread 

 into the Russian literature, there appeared some new views as to the causes of 

 aging in higher organisms. An unusual variation of the theory of the lack of 

 vitality of the somatic cells (in contra-distinction to the full vitality and potential 

 immortality of the germ cells) was developed by V. Krasheninnikov (1924). 

 He believed that the somatic cells receive an insufficient supply of certain sub- 

 stances that are important for their vital activity at the very time of their 

 formation. 



"The somatic cell at its very birth from the germ cell already differs sharply 

 in its morphological structure from the germinal elements. The characteristics 

 of the internal nature of the somatic cell determine its future fate and its specific 

 dependence on the organism as a whole, as well as its limited existence. 



"We suggest that the somatic cells, at their very birth from the germ cells, 

 receive a definite and limited store of vital energy corresponding approximately 

 to the time needed for the growth of the sexual elements" (V. Ye. Krasheninni- 

 kov, 1924). In addition to this, for their entire life they systematically supply 

 the germ cells with special substances that are of great genetic importance. 

 All of this leads, at the end of ontogenesis, to a sharp decrease in the biological 

 potential of the somatic cells and to their death. 



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