200 PROCEEDINGS OF THE [March, 1888. 



it dies ; it never develops in the mud or on the mud. As the microscope shows 

 no difference between this ovum and that of other oysters, I was puzzled for 

 some time to learn how this oyster evej developed and reproduced. I believe I 

 have solved this problem, and, in doing so, ascertained the cause of the ex- 

 haustion of these beds. 



I have mentioned the fact that these oysters were at their best during the 

 time that the ponds were used as log ponds, and that soon after the removal of 

 the logs the oyster began to disappear. The pond owners could see no relation 

 between the oyster and the logs, but such a relation did exist. As the egg was 

 killed by falling in the mud, it must have something to keep it above the mud 

 until it could develop to withstand it, this office the logs performed for it. As 

 the egg floated about it became attached to one of these floating logs, and if 

 the log remained many months in the pond every part of its surface under the 

 water was covered with young oysters, and as this increased its gravity, it soon 

 sunk to the bottom. All the oysters on the under side were killed, but those 

 above the mud developed rapidl5^ At the end of the second year they were 

 quite large enough for transplanting, but in the Pond Oyster this was never 

 done ; in the bay oyster it is at the present time the usual custom in the busi- 

 ness of cultivating the oyster ; the Pond Oyster was always left entirely alone, 

 until it was " picked," as the gatheruig of them was called. 



At this stage of the second year I gathered a few from a log and placed them 

 on the mud with great care, and ia about two months two-thirds of them were 

 dead. It was evident that the mud had killed them, so I studied the logs bear- 

 ing oysters in the pond closely to find the reason. Very soon after a log enters 

 one of these ponds the Teredo attacks it, and, if lying on the mud, in about 

 three years entirely destroys it, this gives the oyster time to develop gi'adually 

 to the conditions of its surroundings, for the log is, during this time, slowly set- 

 tling in the mud, where, at the end of the third year, it begins to fall to pieces, 

 and the oysters clinging to it are gradually lowered in the mud, and as small 

 deposits of mud fall on them at each tide, they, of necessity, learn to clear 

 themselves of it. In the course of time the log completely disappears and the 

 oyster is left to itself ; if any hard substance comes in contact with it, it soon 

 attaches itself to it apparently in an effort to keep above the mud. The work 

 of clearing itself of the mud causes an unusual development of the miiscle that 

 closes the shell ; in the Pond Oyster it is at least one-third larger than in the 

 bay oyster. 



It will thus be seen why the logs are essential to the life of this oyster. The 

 few that are now to be found are about the remains of some old log that has 

 drifted into the pond and been destroyed by the teredo. 



An experiment was made some time ago, of placing stakes upright in the mud 

 standing about two feet above it, so as to catch the eggs as they float about, as 

 is done in Europe where oyster culture is a science ; this experiment promised 

 success the first year, but the teredo was so active that it cut off the stakes at 

 the surface of the mud and destroyed them so rapidly that the oysters were 

 thrown into the mud too suddenly and only a few survived. If we compare a 

 pond oyster, out of the shell, with a bay oyster, we observe not only the tough- 



