The comparative statistical approach to the problems of aging and the 

 human life span first appeared in the Russian literature on ontophysiology in a 

 study by K. A. Andreyev (1871): "On mortaUty tables." He set the task of 

 "finding a correlation between the mortality rate and the various factors that 

 influence it; in other words, of finding an analytic formula in which the mor- 

 tality rate would be expressed as a function of all the factors that influence it." 

 It is interesting that the critical age for males, i.e., the age that he regarded as 

 most dangerous to males (the greatest percerttage of deaths), was given by him 

 as between 40 and 45 years. 



Thirty-two years after this study, the prominent physical chemist P. D. 

 Khrushchev (1903) studied in detail, by the statistical method, the causes of 

 death at each age and the problem of the natural duration of human life. 



He showed that the mortality curve was very high for early infancy, 

 dropped by 14 years, gradually rose to the age of 71.5 years, then sank [tr.: sic], 

 soon meeting the abscissa at 106 years. Here we find support for Mechnikov's 

 view that ordinary old age is pathological old age and that the great majority 

 of deaths are premature. Having estabUshed the five critical periods in human 

 life, Khrushchev came to the conclusion that there are no "sharply detached 

 and entirely independent ages. Life proceeds smoothly and continuously from 

 the beginning to the end; strictly speaking, there are no individual ages but 

 rather five special groups of causes and conditions that create life and lead to 

 death; the majority of them act over periods of many years, others for almost 

 the entire lifetime, but they predominate during certain years of existence, 

 when it is especially convenient to recognize, study, and investigate them." 



During the 80's and 90's of the last century, the investigations of the dis- 

 tinguished Russian zoologists N. A. Kholodkovskiy (1882) and V. M. Shimke- 

 vich (1893) and the eminent physiologist I. R. Tarkhanov (1891) were directed 

 to development of theories of aging. Kholodkovskiy was particularly interested 

 in the problem of the existence of natural death among protozoans and the 

 genesis of death in higher animals. Shimkevich regarded aging as the result of a 

 peculiar degeneration of the tissue cells, due to an imperfect process of karyo- 

 kinesis: "It seems to me that it is in this imperfection of the process of division" 

 (the fact that it is not possible to divide the biophores in a strictly equal manner 

 between the daughter cells, V. N.) "that we should seek the cause of aging of 

 organisms and degeneration of cells ... If Nature could develop a cell with an 

 ideally exact structure and with mathematically accurate division, it would 

 create immortality." 



Tarkhanov formulated the concept of death as the exhaustion of a hypo- 

 thetical substance present in limited amounts in the fertilized ovum. This 

 substance, bound to the nucleus, is parceled out, in the course of metazoan 

 multiplication and differentiation, into "so many trillions and quadrillions of 

 particles that, as a result of their endless division in the course of cell multipli- 

 cation, they must attain such minimal magnitudes that they are no longer able 

 to exert any creative force, and then they cannot overcome the damage incurred 

 during life . . . The cause of natural death is not the wear and tear on the 

 cells themselves but rather the progressive reduction of the ability of the cells 



