OBSER VA TIONS ON INSECTS. 349 



their holes, but keep the ends of their tails fixed therein, 

 so that on the least alarm they can retire with precipitation 

 under the earth. Whatever food falls within their reach 

 when thus extended they seem to be content with such as 

 blades of grass, straws, fallen leaves, the ends of which they 

 often draw into their holes ; even in copulation their hinder 

 parts never quit their holes ; so that no two, except they lie 

 within reach of each other's bodies, can have any commerce 

 of that kind ; but as every individual is an hermaphrodite, 

 there is no difficulty in meeting with a mate, as would be 

 the case were they of different sexes. WHITE. 



SNAILS AND SLUGS. 



The shell-less snails called slugs are in motion all the 

 winter in mild weather, and commit great depredations on 

 garden plants, and much injure the green wheat, the loss of 

 which is imputed to earth-worms ; while the shelled snail, 

 the <epeoiKos, does not come forth at all till about April 

 10th, and not only lays itself up pretty early in autumn, in 

 places secure from frost, but also throws out 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 

 under ground. 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 



