BIRTH, GROWTH AND REPRODUCTION OF OYSTERS. 103 



^ inches by 5 inches. On placing some of the contents 

 of the ovary on a piece of glass, and mixing a little sea- 

 water with it, a most extraordinary scene presented itself, 

 under a inch power magnifying 500 times. The ova 

 were not nearly so large as those from the Burnham oysters 

 mentioned before : they were of two distinct sizes, and 

 very slightly oval, the larger being about four times the 

 size of the smaller ; the smaller were moving about by 

 means of their cilia very actively, while the larger ones 

 were stationary and round, with a slightly darkened mar- 

 gin, as in those from Burnham. The smaller ones came 

 into frequent contact, and adhered to the larger ones, 

 sometimes singly, and at other times in groups ; when 

 such was the case they moved, as if tugging at the larger, 

 and in the apparent effort occasionally let go their hold, 

 and, as it were, sprang from the larger ; sometimes a small 

 one would come in contact with a large one, without 

 attaching itself. After observing them for about ten 

 minutes, the whole became quiescent. I placed some 

 more of the contents of the ovary under the microscope ; 

 but it was far less lively than the first portion observed, 

 probably in consequence of exposure to the air. I have 

 only observed oysters precisely in this state five or six 

 times, as it is scarcely possible out of a large number, even 

 if obtained from the same locality, to find two in similar 

 stages. I did not either observe the rounded bodies, with 



radiating lines, in those last mentioned The 



above extracts will be all that is necessary to introduce 



here From them I think that it is perfectly 



evident that the .oyster is ovoviviparous and monoecious. 

 I am aware that it is even now the opinion of some fisher- 

 men that they are dioecious ; but although I have exa- 

 mined hundreds of both those which are, as it is termed, 



