STRUCTUEE OF SKATE S EGG. 



231 



In April, 18G9, Mr. Thomas forwarded to mc two 

 speciraeiis of eggs of the skate. There were altogether 

 twelve of these eggs ; two only were fully develoxDed. 

 They were enclosed in a membrane. The eggs which 

 were not developed had no coats on them, but resembled 

 the yolk of liens' eggs. The ]3arent fish weighed about 

 SOlbs. , and is described as a *' Bashaw skate.'' (Query : 

 why Bashaw ?) It had no thorns on its back, but on its 

 wings only. It was probably Raia oxijrhijnchus. Each 

 egg is of an oblong shape, and may be likened to a hand- 

 barrow, for fi-om each corner there projects two horn-like 

 processes. The total length, not including the horns, 

 is eight inches; breadth, three inches. The shell of the 

 egg consists of a horn-like substance, feeling to the 

 touch like a sheet of moistened leather. This horny 

 substance is called keitene. It is analogous to the sub- 

 stance which forms the horny wings of beetles. Th§ 

 two ends of the egg difier in appearance : one end is 

 permanently soldered up ; at the other the two sheets of 

 horn-like material are so arranged that when the young 

 fish inside is about to be born they will give way and 

 allow the young fish to struggle out. One of the eggs, 

 at the end where the young one's hall door is situated, 

 presents a feature not observable in the other — a string 

 or rope is attached to each side of the egg just above 

 the origin of the horns. This rope is made in the form 

 of a string composed of the same material as the shelL 

 After running the length of about five inches, these 

 strings join and form an entangled mass like a small 

 bunch of tow. There can be no doubt but that the fish 

 anchors her egg, and these ropes act as "guy ropes " to 

 keep it steady when floating in the water. 



On opening one of these eggs, and turning away one 

 side like a trai3-door, I find the contents consist of a mass 



