VARIOUS PAKTS OF NATURE 345 



appears from their sinuous tracks on the soft muddy soil, perhaps 

 in search of food. 



When earth-worms lie out a-nights on the turf, though they 

 extend their bodies a great way, they do not quite leave 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 ex- 

 tended, 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. 1 



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 inj ure the green wheat, the loss of which is 

 imputed to earth-worms ; while the shelled snail, the <epeoi/cos, 

 does not come forth at all till about April 1 Oth, 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 is plain that 

 a defect of warmth is not the only cause that influences their 

 retreat. 



1 [Sessile or slow-moving animals are often hermaphrodite, e.g., cirripeds, tuni- 

 cates, polyzoa, oyster, land-snails ; so are internal parasites, like tape-worms and 

 flukes. White's explanation of the hermaphrodite condition of earth-worms accords 

 with modern knowledge.;] 



