OF MASSACHUSETTS. 11 



report only valuable for comparative purposes. In addition to these 

 publications the following papers proved of special value in the work: 

 Drew (1) was of great assistance in studying the embryology and in 

 preparing the chapter on a,natomy; Jackson (4) furnished considerable 

 help and useful methods in tracing the post-embryonic development; 

 and Kellogg (6) was found a most comprehensive and valuable paper 

 for general reference work. 



The writer is deeply indebted to Dr. George W. Field for his general 

 supervision and helpful advice in the investigations and in the prepara- 

 tion of the report; to Prof. James L. Kellogg of Williams College, and 

 Prof. Gilman A. Drew of Maine University for their kindly criticism; 

 and to the scallop fishermen of Massachusetts for their friendly assist- 

 ance. More especially is acknowledgment due to the assistants in the 

 investigation. In the summer of 1906 W. H. Gates and C. L. Savery 

 ably assisted in the post-embryological investigations and general growth 

 experiments. During the summers of 1907, 1908 and 1909 W. G. Vinal, 

 together with D. L. Belding, brought the embryological and post-embryo- 

 logical work to a completion. The work of aU three assistants, particu- 

 larly the continued investigations by W. G. Vinal, is worthy of special 

 commendation. 



Methods of Investigation. — The greater part of the work on the scal- 

 lop was conducted at Monomoy Point in the town of Chatham. Near 

 the end of this point an enclosed body of water, some 6 acres in area, 

 connected with the ocean by a shifting channel through which the tide 

 passed every twelve hours, was acquired by the State for experimental 

 purposes. This body of water, called the Powder Hole, is a natural 

 breeding ground for shellfish, and proved an excellent place to study their 

 life history and habits. A few scallops were found in the Powder Hole 

 at the beginning of the investigations; more adults were brought there 

 for breeding purposes and the basin was transformed into a natural 

 aquarium. In this way it was possible to keep close observation on 

 several successive generations of scallops in regard to their growth and 

 length of life under completely natural conditions. A small laboratory 

 was erected on the shore, and a raft 20 feet long by 10 feet wide was 

 securely moored in the deepest part of the cove. The raft proved an 

 invaluable aid in catching and rearing the young, some of the most 

 important experiments being conducted on it. 



While Monomoy was the central station for the scallop work, observa- 

 tions were made in other parts of the State under as diverse conditions 

 as possible. Records of the spawning, growth, migration and habits 

 were kept at Edgartown, Nantucket, Chatham, North Falmouth, Marion 

 and Monument Beach. In this manner the entire scalloping territory of 

 the Commonwealth was under surveillance. Under chapter VII. the 

 specific methods of work will be given in greater detail. 



The Scallop Family. — The scallop belongs to the class of moUusks 



