20 HISTORY OF THE OYSTER. 



spawning had the margins of the bronchise 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 ^-inch power magnifying 500 

 times. The ova were not nearly so large as those from 

 the Burnhain 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 



