Page:Natural History, Mollusca.djvu/102

From Wikisource
Jump to: navigation, search
This page has been validated.
90
PULMONIFERA.—HELICIDÆ.


A moist state of the atmosphere combined with a certain degree of warmth, though not essential to life, is necessary to the healthy performance of its functions in the Snails. On the approach of winter in cold or temperate climates, they hide themselves in protected situations, where they construct, in a manner presently to be described, a tight chamber, within which each individual sleeps away the cold season in a torpid state. During the summer, a continuance of dry weather will induce a similar retirement and a similar torpidity, though more brief in its duration.

The great majority of the species deposit a number of eggs glued together into a mass, and concealed under rubbish, the bark of decaying trees, dead leaves, or moss, or beneath the surface of the ground. Those of the Garden Snail (Helix aspersa) are soft, semi-transparent, and about as large as small peas; those of many foreign species are oval, and are enclosed in a firm, white, calcareous shell, like those of birds. Some of these are of considerable size. That of the magnificent Bulimus hœmastoma, from the West Indies, is as large as a blackbird's egg, and that of Bulimus ovalis from Brazil still larger. The latter species has produced eggs in England. A specimen had been presented to the Horticultural Society, and was kept in their conservatory at Chiswick. At first it appeared rather sickly; but after it had been kept in the hot-house for some time, it recovered, and began to move about. Mr. Booth, who was on the spot, says—"It cannot now be correctly ascertained when it produced the first egg, but it was very shortly after its arrival—I should think about the beginning of November. This egg was sent