17 
described as employed by the young dog-fish. Examining the reason 
why the eggs of the skates and rays were so seldom cast upon the 
sea-shore until the young one was gone, and the shell had served 
its purpose, he remarked that, thanks to the facilities of observation 
at the Brighton Aquarium, he had been enabled to answer this 
question. The egg-case of the rays is covered on its convex side 
with a mass of agglutinated fibres which, when the egg is placed in 
a jar of water, are seen floating out around it like a dense growth 
of felted conferve, and extending along its edge like a broad web. 
When the egg is first laid, this webby mass is in a glutinous 
condition, and adheres to whatever it touches. The egg is deposited 
with the convex side upwards, the proper position of the future 
fish, and it appears to be the habit of the parent to cover it by a 
peculiar motion of her fins with the debris of the bottom on which 
she lies. ‘The stones, shells, sand, &c., stick tightly to the gummy 
garniture, which hardens almost instantly, and thus the egg is 
weighed down by the substances adhering to it. Some eggs of the 
‘spotted ray,” laid in the tanks in June last, were covered up in 
this manner, although others were merely deposited in the shingle. 
_ The rays, like other flat fishes, are, owing to their conformation 
_ and habits, rather troublesome in an aquarium. The flapping of 
their broadly-expanded bodies and lateral fins stirs up the deposit 
at the bottom of their tank, and causes the water to become turbid. 
At Brighton, therefore, it had been found expedient to keep only 
_ sufficient specimens to illustrate the various species procurable, 
and consequently only a few of their eggs had been found there 
_ deposited, some of which had not been fertile. Still, from the 
_ little material thus placed under his observation, he was enabled to 
_ record important results. The eggs were not translucent, like those 
of the dog-fishes, and so it was impossible to judge with certainty 
of their contents ; but although they had only two which they knew 
_ contained living embryos, Mr. Parker’s work was so important to 
_ Bcience that he (Mr. Lee) felt justified in arresting the development 
_ of one of them at the end of the sixth week after its extrusion by 
_ immersing it in spirits of wine, and handing it to the distinguished 
- anatomist, who considered it one of the most valuable and instruc- 
_ tive specimens he had ever received. The other egg was successfully 
_ hatched soon after the expiration of the fifth month, but as the young 
fish, when it left its case, had still a portion of the umbilical sae 
attached to it, and unabsorbed, he had reason to believe that its 
exit was prematurely caused by unskilful and incautious handling ; 
that if left to itself it would have probably remained in the egg for 
‘some time longer, and that its true period of development is as 
‘nearly as possible the same as that of the dog-fish—namely, six 
months. From specimens obtained at Margate, he was enabled to 
‘show the position of the young ray in the egg after it assumes its 
proper form. ‘The two sides of the body were folded over on the 
