THE MOLLUSCA - 109 



for several years, one of the most extraordinary being related by 

 Gaskoin : 



" Specimens of H. lactea were purchased from a dealer in 

 whose drawer they had been for two years. This dealer had 

 them from a merchant at Mogador, who had kept them for more 

 than that time under similar conditions. One of these specimens, 

 on being immersed in water, revived, and in April, 1849, was placed 

 quite alone under a bell jar with earth and food. In the end of 

 the following October, about thirty young H. lactea were found 

 crawling on the glass.'* 1 



Slugs and snails are only too well known to gardeners on 

 account of the wholesale way they destroy the foliage of plants, 

 and their particular fondness for tender young shoots makes these 

 molluscs one of the most troublesome of pests. But snails and 

 slugs are by no means always strict vegetarians ; many Species 

 are carnivorous to a greater or lesser extent. The Great Black 

 Slug (Arion ater) will devour living earth-worms or feed upon dead 

 animal matter of any sort that comes in its way. In captivity 

 it will enjoy a meal of raw beef, and when neither animal nor vege- 

 table food is to be had, this extraordinary slug has been known 

 to devour newspapers, sand, and even soap. Both slugs and 

 snails are often guilty of cannibalism ; and if several are shut up 

 together it is no uncommon thing for them to fall upon and devour 

 each other. A large European snail (Stenogyra decollata), when 

 shut up with other species, is said to devour them shell and all ; 

 while some of the larger slugs, when handled, will sometimes bite 

 and rasp their captor's hand. 



Snails and slugs possess the " homing " instinct in a very 

 marked degree, and after their nocturnal excursions in search 

 of food will return with great regularity to the same hiding-place. 

 If ejected from their home and flung to a distance of several yards 

 the molluscs will almost invariably be found again in the same 

 position as before, when sufficient time has elapsed to enable 

 them to creep home. They are said, too, to show signs of marked 

 intelligence. Darwin gives an interesting account of a couple 

 of Helix pomatia, one of which was sickly, placed in a small, ill- 

 provided garden. The stronger of the two disappeared over the 

 wall into the next garden, which was well furnished with food. 



1 Ann. Mag. Nat. Hist. (2) ix., p. 498. * " Descent of Man," i., p. 325, ist edit. 



