20 HISTORY OF THE OYSTER. 



spawning had the margins of the bronchiae and mantle 

 blackish, the others were of the usual colour of oysters 

 in season. I placed some of the spawn freshly taken 

 from the ovary in salt water, made after Gosse's receipt, 

 in a glass-tube ; they gradually sank to the bottom, 

 but at first appeared lively. 



" May 23. Received some oysters from Llandudno 



in Caernarvonshire; they were of very large size, 



measuring 4^ 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 J-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 margin, 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 



