BULLETIN OF THE UNITED STATES FISH COMMISSION. 289 



Vol. Ill, jYo. 19. Washington, D. C. Sept. 18, 1883. 



One advantage of oyster culture in the Chesapeake over that prac- 

 ticed in Long Island Sound and the more northern waters is, I believe, 

 to be noted in the fact that starfishes are not as abundant; nor have I 

 ever heard that they were as destructive as they are farther north. The 

 experience of Messrs. Pierce & Shepard proves conclusively that what 

 applies to the practice of shell-planting in Long Island Sound is equally 

 applicable in the waters of Chincoteague Bay, and, inferentially, in those 

 of the Chesapeake. 



ENEMIES. 



There are some " drills," or boring whelks, which are found in Chinco- 

 teague Bay', that bore into the shells of living oysters and cause some 

 destruction, but not, so far as I could learn, to a serious extent. 



These molluscan enemies of the oyster are found more or less abun- 

 dantly in all waters in which oyster culture is practiced ; and are prob- 

 ably one of the necessary evils to be encountered in the business, to- 

 gether with the boring sponge, which eats into the shells and which 

 seems to be found in greater or less abundance wherever oysters grow. 



PROPER CONDITIONS. 



The idea that a rough, ragged surface is necessary upon which oyster 

 fry may readily catch, is a fallacy. The prime condition that is neces- 

 sary in order that the fry may adhere, and live, to any surface put down 

 for collecting purposes, is that that surface shall be clean and remain 

 so long enough for the young oyster to get large enough to take care of 

 itself in some measure. 



It is doubtless true that where oyster shells are pretty thickly sown, 

 the interstices between the shells serve to some extent to retain the 

 fry whilst they are still in the swimming stage; but rough surfaces 

 are not at all essential, in that we find spat sets as thickly on the smooth 

 inner surface of oyster shells as upon the rough outer one. 



METAMORPHOSIS OF THE FRY. 



When the young oyster ceases to swim, and attaches itself, it un- 

 doubtedly grows considerably after the time of attachment before its 

 valves lose the perfect symmetry of the larval stage. This has been 

 proved by the examinations which 1 have made of the spat caught on 

 the buoys brought to Wood's Holl. This is also evidence that the writer 

 is probably correct in his statement that the young oyster attaches very 

 soon, or within 24 to 48 hours after the eggs have been fertilized, as an- 

 nounced in his paper on the "Fixation of the fry of the oyster," pub- 

 lished in Bulletin United States Fish Commission, vol. 2, 1882, pp. 383 

 to 387. Another fact confirming this opinion is the circumstauce that it 



Bull. U. S. F. C, 83 19 



