REFORMATION OF THE CRYSTALLINE STYLE 267 



The complete dissolution of the styles of these species occurs, 

 however, within a few days at most. I have found the style of 

 Paphya staminea to have entirely disappeared after a starvation 

 period of forty-six hours, and the complete dissolution of the 

 crystalline style of Saxidomus giganteus usually takes place 

 within two or three days. Nelson ('18) has shown that in the 

 eastern oyster, Ostrea virginica, the crystalline style disappears 

 within an hour after the animal is uncovered by a recession of the 

 tide and may be reformed in fifteen minutes after active feeding 

 has commenced again. 



On the other hand, crystalline styles of certain species are 

 found to be very resistant, not readily dissolved, and persisting 

 throughout the life of the animals even when the latter are re- 

 moved from their normal surroundings or when death by starva- 

 tion occurs. This latter group of bivalves includes Siliqua 

 patula, Schizothaerus nuttallii, Macoma nasuta, Mya arenaria, 

 and others. 



Among these Mya arenaria possesses a crystalline style of a 

 very high degree of resistance. It is certainly never dissolved dur- 

 ing the intervals of the recession of the daily tides and presents a 

 remarkable degree of persistence when the clam is placed under 

 unnatural conditions. After eight days of starvation the crys- 

 talline style of Mya is still very firm except at the extremities 

 where it has begun to soften. The end projecting into the stom- 

 ach has been broken down into a jelly-like mass and the oppo- 

 site extremity shows slight indications of dissolution. Mya may 

 be kept alive, out of water and undergoing starvation, for a 

 duration of fourteen days. At the end of this period the crystal- 

 line style shows but a slightly increased degree of dissolution 

 oyer that presented after eight days of starvation. In Siliqua 

 patula and Schizothaerus nuttallii the crystalline style is found 

 to persist throughout the life of the individual, while subjected 

 to starvation, without much noticeable alteration in its sub- 

 stance. The tenacity of life of these species, however, is not so 

 great as that of Mya arenaria. 



In the forms just mentioned, showing crystalline styles with 

 great power of resistance, the style sacs are completely or, as in case 



