262 CHARLES HOWARD EDMONDSON 



shown that the organ rotates, as was suggested by List ('02), in 

 the style sac in a clockwise fashion, when viewed from the an- 

 terior end, thereby serving to assist in the separation of food from 

 foreign substances in the stomach as well as taking the place of 

 intestinal peristalsis. 



A summary of the function of the crystalline style, as recog- 

 nized at the present time, is as follows: the style is pushed for- 

 ward into the stomach by a movement of the strong cilia of the 

 style sac, at the same time slowly rotating in the direction of the 

 hands of a clock, when viewed from the anterior end. The head 

 of the style, being in contact with the gastric shield of the wall 

 of the stomach, is gradually worn away and, during rotation, as- 

 sisted by movements of the cilia of the stomach wall, separates 

 the refuse matter from the food, twisting the latter up into a 

 mass of mucus at the end of the dissolving style where it may be 

 readily acted upon by starch converting enzymes released from 

 the style. 



2. METHOD OF PROCEDURE 



It is apparent that most of the work of previous investigators, 

 with respect to the formation and function of the crystalline style, 

 has been with those types of lamellibranchs in which there is an 

 incomplete separation of the intestine from the caecum in which 

 the style rests. No published reports, so far as the writer is 

 able to determine, describe the formation of the crystalline style 

 of molluscs in which the style sac is completely or almost com- 

 pletely separated from the intestinal tract. 



With the hope of adding some small contribution toward the 

 solution of this problem, the experiments, the results of which 

 are set forth in the present paper, were initiated. 



Working upon the theory that the reformation of the crystal- 

 line style, after extraction from the body of the mollusc, would 

 take place in a normal manner if the animal were kept under 

 natural conditions, it was decided to select a species, remove the 

 crystalline styles from a large number of individuals, restore the 

 animals to their normal surroundings, and by examination at 

 more or less regular inteivals follow the formation and develop- 

 ment of the crystalline style in this particular species. 



