9° 



THE EVOLUTION OF SEX. 



plasma, which the paternal ovum contains, is unused in the upbuilding 

 of the offspring's body, and is reserved unchanged to form the germ- 

 cells of the next generation. . . . The germ-cells no longer 

 appear as products of the body, at least not in their most essential 

 part — the specific germ-plasma; they appear rather as something 

 opposed to the sum-total of body-cells; and the germ-cells of success- 

 ive generations are related to one another like generations of Pro- 

 tozoal But the continuity is rarely kept up by a chain of undiffer- 

 entiated reproductive cells; it depends upon the continuance and 

 unchanged persistence of a minimal quantity of the original germ- 

 plasma. 



