354 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



177.-IVOTES UPOIV OYSTER EXPERIMEIVTS IIV 1883. 



By Lieut. FRANCIS ^VINiSLoW, U. S. N. 



[From letters to Prof. S. F. Baiid.] 



1 have delayed from day to day to inform yon of the progress of my 

 experiments at Hampton, lioi)ing that I would be able to announce some 

 definite result, but we have bad such bad luck since the middle of June 

 that as yet we have been unsuccessful in securing the attachment of the 

 spat. Our first experiments were full of promise. 1 found, as I wrote 

 you, a number of young oysters fastened to the glass collectors in my 

 apparatus and at about the same time Dr. Brooks found them in his 

 troughs ; but no subsequent experiments have brought about like results. 

 We found, however, that there was no difficulty in keeping the young in 

 the troughs after the shell had formed, and after experimenting M'ith my 

 apparatus (an arrangement of glass tubes) for a month I concluded to 

 have a number of wooden troughs made, and after depositing oysters 

 in them, keeping up a constant current of water until the oysters had 

 either disappeared or attached. The troughs, four in number, are 4 

 inches wide, and 2 inches deep, with a total length of G4 feet. Parti- 

 tions are i)]aced at an angle with the sides, so as to intercept the water 

 and increase the length of the current and form as many eddies as pos- 

 sible. The bottom and sides we have covered with glass and shells for 

 "cultch." The length of the current is 110 feet and over four hundred 

 eddies are formed in it. The young oysters, after the shells have de- 

 veloped, are placed in the head of the troughs, and though exposed to 

 a strong, steady current of water, which is constantly changed by means 

 of a steam pump which is kept going night and day, very few escape 

 from the lower end, the majority remaining in the eddies. Those at 

 present in the troughs have been there over two weeks and though we 

 have not of late found any on the glass slides, we have washed them 

 off the shells and so far as I can judge a considerable number are still 

 living. Our greatest trouble, an unaccountable one, has been in secur- 

 ing the artificial impregnation of the eggs successfidly. Not once iu 

 twenty times do the eggs advance as far as the first stages of segmen- 

 tation and during the last two weeks we have been successful but once 

 in carrying the eggs to the swimming stage. Neither Dr. Brooks nor 

 myself can explain the failure ; the difticulty is one we never experienced 

 before. We have varied every influencing condition and have used 

 oysters, from every locality in this vicinity without effect. Since the 

 middle of June we have not succeeded ten times, though we have fer- 

 tilized eggs nearly every day. The oysters are now nearly through 

 spawning, and but little more can be done this season. I have written 

 to New Haven to find out the condition of oysters in the sound and 



