THE OYSTER. 6 1 



of its embryology does not end with the facts, and we 

 shall find among the purely speculative deductions 

 which naturalists have drawn from it much which will 

 help us to appreciate and to utilize the oyster as a 

 food resource. 



When the ^gg is first laid it is a little globule of 

 living matter, with no visible indication of the struc- 

 ture of an oyster, although it is a potential oyster, and 

 is destined to build up, slowly, but surely, from the 

 vegetable food in the water, every part of a complicated 

 adult like that which produced it. It is not, however, 

 an oyster in miniature. Our utmost means of observ- 

 ation do not reveal in it anything whatever, at all like 

 the structure of the adult. Such structure as the 

 microscope does show is the structure of a cell, like 

 one of those which make up the oyster's body, and 

 the process of development is at first simply a process 

 of cell-multiplication, not the unfolding and enlarge- 

 ment of a rudimentary oyster. If we compare an 

 adult oyster to a brick house, then the ^g% corre- 

 sponds to a brick, not to a little house, and develop- 

 ment begins by cell-division or the multiplication of 

 bricks rather than by the growth of a little house. So 

 far as the microscope tells us, there is nothing like an 

 oyster in the ^^'g, yet it must be there in some form, 

 for an oyster's ^gg never becomes anything except an 

 oyster. If we knew only the higher animals we might 

 suppose that the development of an ^gg 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 ^gg, for this is thrown on the world to take 

 care of itself before its development begins. The 



