204 FACULTIES OF BIRDS. 



Those animals which lie torpid during winter 

 are usually careful to provide a warm and well 

 sheltered domicile for their long* sleep, and it is not a 

 little interesting to observe the proceedings of 

 different species. The edible snail (Helix pomatia, 

 LINN.), for example, found in the middle districts of 

 England, but supposed to have been introduced from 

 the Continent in the sixteenth century, forms at the 

 end of autumn a very curious winter cell. When 

 at liberty, it constructs this cell of earth, moss, and 

 withered grass, by means of its muscular foot, 

 enlarging the cavity by turning itself round, and 

 forming the roof by carrying up portions of earth and 

 moss*. But, according to Mr. Bell, " it is not by 

 the pressure of the foot and the turning round of the 

 shell that this is principally effected. A large quantity 

 of very viscid mucus is secreted on the under surface 

 of the foot, to which a layer of earth or dead leaves 

 adheres ; this is turned on one side, and a fresh 

 secretion being thrown out, the layer of earth mixed 

 with mucus is left. The animal then takes another 

 layer of earth on the bottom of the foot, turns it also 

 to the part where he intends to form the wall of his 

 habitation, and leaves it in the same manner, re- 

 peating the process until the cavity is sufficiently 

 large, and thus making the sides smooth, even, 

 and compact. In forming the dome or arch of the 

 form, a similar method is used, the foot collecting on 

 its under surface a quantity of earth, and the animal 

 turning it upwards, leaves it by throwing out fresh 

 mucus, and this is repeated until a perfect roof is 

 formed f." 



We brought a pair of these animals from the woods 

 of Godesberg on the Rhine in 1829 ; and as they 

 were kept under an inverted glass with only a few 



* M. Gaspard in Majendie's Journ. de Physiologic, ii. 295. 

 t Zoological Journal, i. 94, note, 



