102 THE POPULAR SCIENCE MONTHLY. 



torum) 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 Cali- 

 fornia, alive six years without food.* Many other such cases are 

 known. 



Strangely enough, the slugs undergo no such period of hiberna- 

 tion, 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 

 aestivates and forms a parchmentlike epiphragm from the edges 

 of the shell to the place of attachment and when it returns to ac- 

 tivity 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 re- 

 tiring 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 count- 

 ed from two hundred and fifty to three hundred of them thus 

 tucked snugly away in a single tuft of grass. It is indeed for- 

 tunate 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 ver- 

 tically from moisture ; and I have gathered numbers of them in 



* For an account of this, see a paper On the Vitality of Certain Land Mollusks, by R. 

 E. C. Stearns, Proceedings California Academy of Sciences, October 18, 1875. 



