66 THE OYSTER. 



than by the growth of a little house. So far as the 

 microscope tells us, there is nothing like an oyster in 

 the egg, yet it must be there in some form, for an 

 oyster's egg never becomes anything except an oyster. 

 If we knew only the higher animals we might suppose 

 that the development of an egg is guided in some way 

 by the influence of the parent ; but there can be no 

 such directing influence in the case of the oyster egg, 

 for this is thrown on the world to take care of itself 

 before its development begins. The force which 

 causes it to become an oyster cannot come from par- 

 ental 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 egg itself, and when the microscope 

 was first used to study the early stages of animals, 

 naturalists thought they could discover in the egg 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 



