Page:Natural History, Mollusca.djvu/124

 fragile in their structure, and although many—indeed I may say numbers—were caught, yet very few in comparison were found to be in a perfect condition, some being deficient in one, two, or more fins, and others being completely crushed. Not one of the specimens caught on this occasion, or during the voyage, had the silvery line or streak running down the back, from the head to the extremity of the tail, branching off also to the fins, and along the centre of each of the digitations. Several Porpitæ were also captured in the net at the same time with these animals, and served as food for them.

"It caused much regret to see the change death produced in the beauty of these interesting little animals, and all means of preserving them were found to be useless. When placed in spirits, the digits of the branchial fins speedily became retracted; the beautiful purple gradually faded, and at last disappeared, and the delicate pearly white of the under surface of the body and fins peeled off and disappeared.  Thus did this beautiful Mollusk become decomposed in less than the space of an hour.  Some Mollusks quickly lose their colour after death, but retain their form for a long time; but these speedily change after death, both in form and colour, and the beauty before so much admired perishes, never to be regained.

"When taken in the hand, the under surface of the animal soon becomes denuded of the beautiful pearly white it previously had, and at that time appears like a small transparent bladder, in which a number of air-bubbles are observed, together with the viscera. On the abdomen being laid open, a large quantity of air-bubbles escaped; and perhaps