no Our Food Mollusks 



Previous to the year 1879, the anatomy of the Amer- 

 ican oyster had been studied very little, and nothing was 

 known of its breeding habits or development. A few 

 European biologists had found that the oyster of their 

 northern coast was hermaphroditic, that the eggs were 

 fertilized and developed within the body of the parent, 

 and that they were retained there for some time. It was 

 supposed that the American oyster was structurally and 

 functionally very much like its European relative. 



In the year mentioned, the late Professor Brooks of 

 the Johns Hopkins University, made some observations on 

 our form that have become classic, and in their publica- 

 tion showed, among many other things, that the Amer- 

 ican oyster is unisexual, and that the eggs are fertilized 

 and develop outside the body of the female. He also dis- 

 covered that it was possible, at will, to bring about the 

 union of the sexual cells in a dish of water, and to ob- 

 serve the process of segmentation and the formation of 

 organs. He was not able, however, to devise means of 

 keeping the swimming embryos alive until they had be- 

 come attached. 



In performing the experiment, Professor Brooks 

 simply opened the ovaries of a mature female with a 

 scalpel and pressed the almost microscopic eggs into a 

 dish of water. From a mature male he obtained a few 

 drops of the spermatic fluid in the same way, and mixed 

 them with the ova, the great majority of which became 

 united with male cells. 



Attention was at once attracted by this experiment. 

 In the light of what had been accomplished in fish culture 

 by means of artificial impregnation, possibilities seemed 

 great in this case. Others took it up with enthusiasm. 

 Before very long what purported to be an improvement 



