1018 THE PHYSIOLOGY OF REPRODUCTION. 



living matter are in some way obviated or neutralized by the 

 growth changes. Rubner suggests, somewhat in the line of Dar- 

 win's theory of pangenesis and of Weissmann's theory of the cause 

 of death in the somatoplasm, that the body-cells give off certain 

 molecular complexes which are necessary to the growth processes, 

 and these complexes are taken up by the reproductive cells. After 

 the animal has reached the period of puberty, of reproductive 

 power, and provision is thus made for the perpetuation of the 

 species, the individual organism is depleted of the power of growth 

 and senescence and death become inevitable. There are no actual 

 facts at present to support such a view and, indeed, it is at variance 

 with prevalent ideas regarding the lack of direct influence of the 

 somatic cells upon the germ cells. 



