178 INTRODrCTION TO CONCHOLOGY. 



Appian beautifully notices the creeping movements of 

 this curious little animal, in the following characteristic 

 lines : — 



" "When loved Arcturus leaves the main to rise 

 A star bright shining in the evening skies, 

 Then prune the vine ; 'tis dangerous to delay. 

 Till with complaints the swallow breaks the day, 

 "When \^'ith their domes the slow-paced snails retreat 

 Beneath some foliage from the bm'ning heat. 



And scarcely has the burning heat of summer been suc- 

 ceeded by the chills of autumn, than these slow-paced 

 creatures begin to hibernate, or retire within their domes. 

 This is effected by covering the entrance to their shells 

 with an irregular layer of mucus, which gradually hardens, 

 and forms a calcareous door, that effectually excludes the 

 cold and wet. Thus protected, they remain torpid through 

 the winter ; but with the return of spring, and the opening 

 of green leaves, the calcareous covering is either broken 

 by the eagerness of the mollusk to come forth, or else 

 becomes absorbed. 



The smallness of his domicile prevents the snail from 

 la}dng up a supply of food, but this is rendered unnecessary 

 by his extraordinary powers of vitality and abstinence, — in 



