50 



BACTERIOLOGY OF THE OYSTER. 



set on edge and allowed to drain thoroughly. The surplus water was 

 removed with filter paper. The oyster was then seared with a hot 

 spatula over the stomach, over the intestine, where it bends sharply 

 upon itself on the ventral side and on the rectum just above the anus. 

 An incision was then made into these three parts of the alimentary 

 tract with sterile scalpels and a sterile capillary pipette inserted and a 

 portion of the contents removed and plated upon agar which was 

 grown at room temperature for two days and examined for red colo- 

 nies. Control samples of the shell liquor were plated before the inocu- 

 lation with B. prodigiosus and these were negative in all cases. In 

 the first experiment the time of examination after inoculation ranged 

 from thirteen hours to twenty-seven hours. In the second experiment 

 the time varies from five hours to seventy-four hours. 



Table Shoiving Length of Time at which B. Prodigiosus was Isolated from Different 

 Parts of the Alimentary Tract after the Inoculation of the Gill Chamber. 



