HELIX POMATIA. 



other by an imperceptible slime. When the snail leaves the 

 egg, it is observed with a very small shell on its back, having 

 only one whorl ; but in proportion as it grows, the shell in- 

 creases in the number of its spiral turns. The addition is 

 always at the mouth, the first centre still remaining, the ani- 

 mal sending forth from its body that slime which hardens into 

 a calcareous substance, and is still fashioned into similar con- 

 volutions. Thus fitted with its covering, which is light and 

 firm, the snail finds itself well defended from external injury; 

 and it has only to retire into its fortress to escape impending 

 danger. It derives its chief subsistence from the leaves of 

 plants and trees, and, although very voracious, is extremely 

 delicate in its choice. When in quest of food, it moves for- 

 ward by means of that broad, muscular skin which is some- 

 times seen projecting beyond the mouth of the shell ; this is 

 expanded before and then contracted with a kind of undulat- 

 ing motion. It is also able to ascend in a perpendicular 

 direction, and has its progress facilitated by means of that 

 viscous excretion which it emits whenever it moves. On this 

 glutinous matter it can proceed slowly and in safety along a 

 rugged path, or ascend trees and fences for the purpose of 

 feeding, and it also descends by the same aid, without danger 

 of falling and injuring its shell. 



At the approach of winter the snail buries itself in the 

 earth, or retires to some hole, where it continues in a torpid 

 state during the severity of the season : thus it sometimes lies 

 torpid for six or seven months, till the genial warmth of spring 

 awakens it to a state of activity; when it quickly makes 

 amends for its long abstinence by feasting on every vegetable 

 substance that falls in its way. Before, however, they com- 

 mence this inactive state of existence, snails close the mouth 

 of their shells with an epiphragma (or covering not attached 

 to or forming a part of the animal), which, stopping it up, 

 entirely protects it from every external injury ; it is composed 

 of a whitish substance, somewhat resembling plaster. In the 

 centre is an exceedingly minute orifice, communicating with 

 the lungs ; and this minute hole, though not large enough to 

 admit a drop of water, is of sufficient capacity for the passage 

 of air. The multiplication of snails is at times prodigious, 

 and it is uniformly observed that a rainy season contributes 

 much to their increase. It has been asserted, and on appar- 

 ently good authority, that snails have been known to revive 



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