HEREDITY. 



Reproduction in 

 Man. 



Continuity of 

 Germ-Plasm. 



Man is just such a complex organism as we 

 have been studying. Anatomically he is com- 

 posed of many millions of cells, each of which is 

 the body of a psychological unit, that performs a 

 specific function in his organism. Psychologically 

 he is a complex soul composed of millions of 

 primary life principles or units. By the co-opera- 

 tion of these life principles, acting through and 

 by means of this complex anatomy, all the func- 

 tions of life, sensation and mentality are carried 

 on. From each of these millions of psychic units 

 there passes, in some mysterious way, a represen- 

 tative principle into a life germ that thus becomes 

 an epitome of the parent's organization. 



As previously indicated, in the lowest forms of 

 life the male and female principles exist in one 

 organism; in such the union of these principles 

 takes place within the parent organism and the 

 new life thus created needs only to be expelled 



cell. In the whole process of development there is a con- 

 stant division of nuclear material, but at no time, except in 

 impregnation, is there a union of the chromatin from two 

 cells. The diminution of the chromatin, which is the conse- 

 quence of the division, is made good only by the assimila- 

 tion and metabolization of non-chromatin material. It 

 therefore follows that the chromatin of the germ-cells (what 

 Weismann calls "germ-plasm") is not and cannot be derived 

 from an^ part of the parent organism; but that, on the 

 contrary, it is a direct descendant of the germ-plasm of the 

 parent germ-cells, and stands to all the rest of the body in 

 much the same relation as does a parasite to its host, show- 

 ing a life independent of the body, save in so far as the body 

 supplies to it appropriate lodgment and nutrition. In each 

 generation, it is supposed, a small portion of this substance 

 is told off to develop a new body to lodge and nourish the 

 ever-growing and never-dying germ-plasm it can transmit 



