302 American Fisheries Society 



For this purpose we conceived the idea of using a 

 centrifugal machine, a De Laval "milk clarifier," by which 

 the tiny oysters could be separated from the water as 

 readily as specks of dirt are separated from milk. At first 

 it might appear that such delicate animals would be in- 

 jured by passing through a centrifugal machine, but we 

 found that, being enclosed in shells which afforded pro- 

 tection, they could be concentrated in the machine with- 

 out injury. In this way millions of little oysters were 

 separated from a large volume of water, and transferred 

 in a small bowl to another volume of water containing 

 fresh food and other necessities of life. The same ma- 

 chine was also used to eliminate from the water dirt 

 and various enemies of the oysters — which are not the 

 less dangerous because they, too, are of microscopic size. 



In an improvised laboratory in the plant of the Blue 

 Point Oyster Company, at West Sayville, L. I., our first 

 trial began on June 10th and led to immediate success in 

 keeping countless numbers of young oysters, developed 

 from artificially spawned and fertilized eggs, for a period 

 of eleven to fourteen days. Five different batches were 

 included in this experiment, and they increased in size and 

 changed in form. All were lost, however, through im- 

 proper attention at a time when the writer was obliged 

 to be absent for a few days. 



New batches were started on July 4th, 5th, 10th, 16th 

 and 21st. These all continued progressively to the "set- 

 ting" stage, and thus for the first time an oyster "set" 

 was obtained artificially under controlled conditions, and 

 when the progress of development could be observed from 

 day to day. By "set" is meant the habit of young oysters, 

 after a preliminary period as free swimmers, of sinking 

 to the bottom and attaching themselves to shells and other 

 hard objects. The time of development from spawning to 

 setting was established by our experiment to be ap- 



