Page:Popular Science Monthly Volume 45.djvu/115

Rh winter under projecting rocks high upon the bluffs of the South Platte River.

In the tropics the process of æstivation is analogous to hibernation, but there is not so complete a cessation of the functions. The same epiphragm is made, and the rest is taken for the same purpose—to avoid the vicissitudes of climate; only in this case it is to escape drought instead of cold. And sometimes the same gregarious habit is observed, and the snails crowd in closer than the occupants of a cheap lodging house. On some of the west Florida keys I have seen Helix Carpenteriana æstivating under grass and logs in such vast numbers that one might scoop them up by the quart; and in the Maritime Alps I have found other species of the land snails piled together by hundreds in hollows of limestone cliffs during the dry season. The strophias either cling to the stems of low bushes or lie at their roots, as do many species of Bulimulus, often in great numbers.

The arboreal species firmly attach themselves to the bark of the trees on which they live and on whose foliage they subsist, and form a solid epiphragm of the consistence of sole leather. On the lower part of Florida and on the keys the magnificent Orthalicus and Liguus, the latter gaudy with bands of yellow, brown, and green, the former a soft cream color, with markings of jet black and brown, live often on such trees as the Jamaica dogwood (Piscidia erythrina) and the Bursera, which shed wholly or in part their leaves during late winter and spring, the dry season. The sight of one of these trees without foliage, and loaded with this strange, glittering fruit, is enough to thrill the heart and stir the blood of any collector, and I shall never forget my first experience with them at Cape Sable. In my eagerness to possess the beautiful things I broke several specimens, as the epiphragm adhered so firmly that the shell crushed before it would loosen, and I could only save them by cutting away the bark.

One wonders why these snails so freely expose themselves during æstivation, when they are utterly powerless to escape from their enemies. Many of these trees, which were full of them, were isolated more or less and were without foliage, and every shell could be seen hundreds of feet away. That they have enemies I discovered afterward as I wandered broken-hearted among the thick scrub of Key West to find quantities of fresh broken Orthalicus lying on the ground, but not one alive. Many of them appeared as though a hole had been picked in them by birds large enough to get out the snail and utterly ruin the shell. In this case death came swiftly and painlessly, no doubt, while they were