THE CYCLE OF LIFE 379 



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Fig. 59. — Chain of embryos (b,) of Enoyrtus fuacioollia, all arising from 

 one ovum, bound together by a chain of mucus (s. ) A\te,r Marohal. 



segregation of the germ-cells is not demonstrable, we know 

 that the germ-cells do not arise from diflerentiated 

 body-cells. They are cells which retain intact the 

 quaUties of the fertilized ovum which gave rise to the 

 parent. Similar material to start with, similar conditions 

 in which to develop — therefore, Uke tends to beget hke. 

 Two famous quotations may make this fundamental fact 

 of germinal continuity quite clear. There is a sense, Galton 

 said, in which the child is as old as the parent, for when 

 the parent's body is developing from the fertihzed ovum, 

 a residue of unaltered germinal material is kept apart to 

 form the reproductive cells, one of which may become the 

 starting-point of a child. To use Weismann's words : ' In 

 development a part of the germ-plasm {i.e., the essential 

 germinal material) contained in the parent egg-cell is not 

 used up in the construction of the body of the offspring, 

 but is reserved unchanged for the formation of the germ- 



