PEOGEESS IN BIOLOGICAL INQUIRIES, 19 2 7 231 



the collections early in August, become numerous by mid-August, 

 and abundant early in September, Spawning appeared to have 

 ceased earlier in 1927 than in the previous winter, but the two sea- 

 sons correspond fairly w^ell. With lamellibranchs, fall spawning is 

 believed to be unusual in cases wdiere it ceased completely in the late 

 winter, spring, and early summer. 



Studies of growth show clearly that the bulk of the market catch 

 through the winter consists of scallops about 1 year old. Therefore, 

 information as to the natural life span of the scallop is of great im- 

 portance. If scallops die soon after attaining their second winter of 

 life, it would be desirable to catch them for market before that hap- 

 pens. However, if they live to spawn in the season following their 

 second winter, it would be distinctly advantageous to the industry 

 to permit some of them to escape capture. In view of the uncertainty 

 as to the exact length of life of the scallop, it is important to fix the 

 dates limiting a closed season against scallop fishing so as to protect 

 the young scallops of marketable size but that have not had an op- 

 portunity to spawn once. 



To determine the natural life span of scallops, various tagging 

 and penning experiments were carried out, with some valuable re- 

 sults. It was shown that very few of the adult scallops that 

 remained in the spring at the close of the fishing season survived 

 until December. Unfortunately, in spite of efforts made to protect 

 them, so many of the scallops on the flats near the laboratory were 

 taken by the fishermen during the scallop season that it was impos- 

 sible to tell how many might have survived if unmolested. 



Mature scallops from various areas vary considerably in size. In 

 general, they are smaller in water of low salinity. Heretofore, there- 

 fore, it was thought that small size was indicative of an environment 

 unsuited to growth, but recent studies have shown that race or variety 

 may have bearing on size. Therefore, tentative arrangements have 

 been made with the department of conservation and development of 

 the State of North Carolina to transfer young scallops from seem- 

 ingly unfavorable regions to others apparently better suited to them 

 in an attempt to determine whether this would improve their size, and 

 also in order to stock with scallops of large size sections that now 

 produce only small scallops. 



In the course of scallop collecting some histological material was 

 obtained, as well as notes on the state of development of the gonads 

 of Ostrea equestris^ the small oyster found to be viviparous and 

 hermaphroditic. In some areas this oyster incrusts the shells of 

 scallops so heavily as to be a nuisance, and it is even held by some 

 persons to be an enemy of the scallop. 



ALASKA CLAMS 



During 1927 investigation of the Pacific razor clam was continued 

 by Dr. F. W. Weymouth, of Stanford University, and H. C. McMil- 

 lin. The measuring of shells collected previously from commercial 

 beds was completed, and norms of growth were calculated for all 

 important localities. 



Examination of the Washington beds after the largest pack in the 

 history of commercial operations had been made showed them to be 



