140 WONDERS OF ORGANIC LIFE. 



cumstances attending the hybernation of the 

 edible snail, (HelLv pomatia,) common on the 

 warmer parts of the continent, and naturalized in 

 Surrey, near Dorking lime-pits. As soon as 

 the first autumnal chills are felt, this species 

 becomes indolent and ceases to eat ; it then 

 collects in considerable numbers on banks, in 

 thickets, and in sheltered nooks. Here the 

 groups hide themselves under grass, dead leaves, 

 and the like, and each forms with the ante- 

 rior part of its muscular foot a cavity, large 

 enough to contain the shell. This being effected, 

 it draws over itself a covering of earth and 

 leaves, and the foot is withdrawn, the collar of 

 the mantle is protruded, and a quantity of air 

 inspired — the orifice of respiration is then closed. 

 When this is done, a fine transparent membrane 

 is formed with its mucus, this being interposed 

 between the mantle and any extraneous substance 

 lying above. The mantle then secretes a quantity 

 of very white fluid over its whole surface, which 

 sets uniformly like plaster of Paris, instantly 

 forming a continuous covering about half a line 

 thick. When this is hardened, the animal 

 separates its mantle from it by another and 

 stronger mucous secretion ; and after a few 

 hours, expelling a portion of the air it had pre- 

 viously inspired, it is enabled to shrink a little 

 further into the shell. It now forms additional 

 layers of mucus, expires more air, and thus 

 retires further into the shell. In this way some- 

 times a fourth, fifth, and even a sixth partition 

 is formed, with intermediate cells filled with uir 



