Page:Popular Science Monthly Volume 45.djvu/114

102 ) which, after being glued to a tablet for four years in the British Museum, was noticed to have discolored the paper of its label, and on being put into warm water it revived; and Dr. Stearns kept a Helix Vietchi from Cerros Island, Lower California, alive six years without food. Many other such cases are known.

Strangely enough, the slugs undergo no such period of hibernation, as they only cease activity in temperate climates during the coldest weather, and when a warm spell occurs in winter they are thawed out into new life. It is indeed curious that these naked fellows should be so much more hardy than their relatives, who wear their great overcoats of shells into which they can wholly retreat, but so it is. Binneya, a Mexican snail, whose shell is not large enough to cover its body, attaches itself to a spot where it æstivates and forms a parchmentlike epiphragm from the edges of the shell to the place of attachment, and when it returns to activity often carries with it this queer addition to its house. Most snails dissolve this when they awaken from their long sleep.

Nature has kindly relieved the operculated land snails from the trouble of making this protection, and when the time for retiring arrives they simply retreat into the shell and close the door behind them. In this condition they are "not at home" to any callers. The long winter's sleep proves disastrous to many of the snails, and in the spring quantities of dead shells will be found huddled together in hollow trees, under rocks, and in their crevices, or buried beneath the leaves and ground with a few survivors among them. Why they thus assemble together to hibernate is difficult to tell, unless it is because "misery loves company."

The succineas are a somewhat amphibious family of air-breathers, and on the approach of winter often crowd together into tussocks of grass or rushes by the edges of streams and ponds. In eastern Colorado and western Nebraska I have counted from two hundred and fifty to three hundred of them thus tucked snugly away in a single tuft of grass. It is indeed fortunate for them that they are wrapped in unconsciousness during the dreary winter of that shelterless, desolate country, with its howling blizzards and snows drifted wildly over the prairies, and it is marvelous that so large a proportion survives. In that dry region water is a luxury that even a fresh-water snail can not always afford; hence their shells are found strewed over the highest table lands, miles horizontally and hundreds of feet vertically from moisture; and I have gathered numbers of them in