Page:White - The natural history of Selborne, and the naturalist's calendar, 1879.djvu/446

424 round the mouth of its shell a thick operculum formed from its own saliva; so that it is perfectly secured and corked up, as it were, from all inclemencies. The cause why the slugs are able to endure the cold so much better than shell-snails is, that their bodies are covered with slime, as whales are with blubber.

Snails copulate about Midsummer; and soon after deposit their eggs in the mould by running their heads and bodies underground. Hence the way to be rid of them is to kill as many as possible before they begin to breed.



Large, grey, shell-less cellar-snails lay themselves up about the same time with those that live abroad; hence it is plain that a defect of warmth is not the only cause that influences their retreat.—.

About the middle of this month (September) we found in a field near a hedge the slough of a large snake, which seemed to