FIG. i. Diagram illustrating WEISM ANN'S theory of germinal 

 continuity. Three generations are represented, with cells of germ 

 plasm shaded, and those of body plasm unshaded; germ plasm con- 

 tinuous from generation to generation, carried over from parent to 

 offspring by zygote (Z) ; impossible for body plasm to perpetuate itself 

 into a second generation. 



