264 CHARLES HOWARD EDMONDSON 



As soon as practicable after the crystalline style has been ex- 

 tracted, the clams should be replanted in selected areas, and 

 each individual so marked that there may be no possibility of mis- 

 taken identity of the specimen, even though months should 

 elapse before it is reexamined. I have used a system of stakes, by 

 which each individual may be identified, with entire success. 



The experiments on the reformation of the crystalline style of 

 Mya arenaria were carried on in the Siuslaw River about four 

 miles from its mouth, between the towns of Florence and Acme, 

 where is located one of the most extensive beds of this species on 

 the Oregon coast. Here Mya grows to a very large size, many 

 specimens I have measured attaining a length of shell of 150 mm. 

 The beds in the Siuslaw River are very accessible and work can 

 be done upon them at a moderately low tide, this locality being 

 a most convenient one in carrying on series of rapidly repeated 

 tests or those running through longer periods of time. 



The physical effect of the operation, as described above, upon 

 the mollusc itself may be indicated by a summary of the result 

 of the entire series of experiments. I have found that approxi- 

 mately 50 per cent of the clams die as a result of the severance 

 -of the style sac and the removal of the crystalline style. In 

 some tests extending over a period of several weeks the death 

 rate ran as high as 75 per cent, while in others, enduring for a 

 similar period, it was as low as 25 per cent. Unless death occurs 

 during the second or third week following the operation, the 

 clams usually recover and regain their normal functions, the 

 wound in the meantime having healed and the severed ends of 

 the style sac usually being completely closed. The success is 

 dependent largely upon the carefulness with which the incision 

 of the style sac is made — a very deep cut destroying the sur- 

 rounding visceral tissue and permitting bacterial infection. Re- 

 sults also show that large, mature individuals survive more 

 readily, apparently having a greater degree of resistance than do 

 young or half-grown ones. 



In general, a higher rate of mortality was reached in experi- 

 ments carried on during the winter than the summer months. 

 However, excessively high water and frequent flooding of the 



