62 THE OYSTER, 



force which causes it to become an oyster cannot come 

 from parental influence, nor can it be due to anything 

 in the external world, for hosts of other animals live 

 in the water with the oyster, and side by side with the 

 oyster eggs float those of starfishes, annelids and 

 countless other animals, all exposed to exactly the 

 same external conditions, and yet each develops after 

 its own kind, and builds up cell by cell an animal like 

 its parent. 



There is no escape from the belief that the directing 

 force is in the ^^^ itself, and when the microscope 

 was first used to study the early stages of animals, 

 naturalists thought they could discover in the ^^^ the 

 little image in miniature of the future animal, and they 

 taught that this exists in a perfect but dormant and 

 unexpanded condition in the egg, and that the process 

 of development is nothing more than the growth and 

 expansion of this germ. 



More careful study with better instruments and im- 

 proved methods has failed to verify this supposed dis- 

 covery, and so far as our present means of research 

 go, they reveal nothing whatever in the ^%% which 

 resembles the adult in any particular, nor do they 

 show anything in the oyster ^g^ which should cause 

 it to become an oyster rather than some other animal. 

 The testimony of all observers, based upon the study 

 of all kinds of animals, is that the ^gg is not compara- 

 ble to the adult in miniature, but to one of the con- 

 stituent cells of its body; that the development of an 

 egg is not the unfolding of a germ, but a process of 

 cell-multiplication. The ^%g divides into a number of 

 cells like itself, and these divide and subdivide until 



