TESTACEOUS FISHES. 



1)8.;! 



four rounds and a- half; but some of the sea- 

 snails arrive even at ten. 



The snail, thus fitted with its box, which is 

 light and firm, finds itself defended in a very 

 ample manner from all external injury. 

 Whenever it is invaded, it is but retiring into 

 this fortress, and waiting patiently till the dan- 

 ger is over. Nor is it possessed only of a 

 power of retreating into its shell, but of mend- 

 ing it when broken. Sometimes these animals 

 are crushed seemingly to pieces ; and, to all 

 appearance, utterly destroyed : yet still they 

 set themselves to work, and, in a few days, 

 mend all their numerous breaches. The 

 same substance by which the shell is originally 

 made, goes to there-establishment of the ruin- 

 ed habitation. But all the junctures arc very 

 easily seen, for they have a fresher colour than 

 the rest, and the whole shell in some measure 

 resembles an old coat, patched with new 

 pieces. They are sometimes seen with eight 

 or ten of these patches; so that the damage 

 must have been apparently irreparable. Still, 

 however, though the animal is possessed of 

 the power of mending its shell, it cannot, when 

 come to its full growth, make a new one. 

 Swammerdam tried the experiment: he strip- 

 ped a snail of its shell, without hurting any of 

 the blood-vessels, retaining that part of the 

 shell where the muscles were inserted ; but it 

 died in three days after it was stripped of its 

 covering : not, however, without making 

 efforts to build up a new shell ; for, before its 

 death, it pressed out a certain membrane round 

 the whole surface of its body. This membrane 

 was entirely of the shelly nature, and was in- 

 tended, by the animal, as a supply towards a 

 new one. 



As the snail is furnished with all the organs 

 of life and sensation, it is not wonderful to see 

 it very voracious. It chiefly subsists upon the 

 leaves of plants and trees ; but is very delicate 

 in its choice. When the animal moves to seek 

 its food, it goes fonvard by means of that 

 broad muscular skin which is sometimes seen 

 projecting round the mouth of the shell ; this 

 is expanded before, and then contracted with 

 a kind of undulating motion, like a man at- 

 tempting to move himself forward by one arm, 

 while lying on his belly. But the snail has 

 another advantage, by which it not only 

 smooths and planes its way, but also can 

 ascend in the most perpendicular direction. 



MO. 57 & 58. 



This is by that slimy substance with which it 

 is so copiously furnished, and which it emits 

 wherever it moves. Upon this slime, as upon 

 a kind of carpet, it proceeds slowly along, 

 without any danger of wounding its tender 

 body against the asperites of the pavement ; 

 by means of this it moves upwards to its food 

 upon trees ; and by this descends without 

 danger of falling, and breaking its shell by the 

 shock. 



The appetite of these animals is very great , 

 and the damage gardeners in particular sustain 

 from them, makes them employ every method 

 for their destruction. Salt will destroy them, 

 as well as soot ; but a tortoise in a garden is 

 said to banish them much more effectually. 



At the approach of winter, the snail buries 

 itself in the earth ; or retires to some hole, to 

 continue in a torpid state, during the severity 

 of the season. It is sometimes seen alone ; 

 but more frequently in company in its retreat ; 

 several being usually found together, apparent- 

 ly deprived of life and sensation. For the 

 purposes of continuing in greater warmth and 

 security, the snail forms a cover or lid to the 

 mouth of its shell with its slime, which stops 

 it up entirely, and thus protects it from every 

 external danger. The matter of which the 

 cover is composed, is whitish, somewhat like 

 plaster, pretty hard and solid, yet at the same 

 time porous and thin, to admit air, which the 

 animal cannot live without. When the cover 

 is formed too thick, the snail then breaks a 

 little hole in it, which corrrcts the defect of 

 that closeness, which proceeded from too much 

 caution. In this manner, sheltered in its hole 

 from the weather, defended in its shell by a 

 cover, it sleeps during the winter ; and, for 

 six or seven months, continues without food 

 or motion, until the genial call of spring breaks 

 its slumber, and excites its activity. 



The snail having slept for so long a season, 

 wakes one of the first fine days of April, breaks 

 open its cell, and sallies forth to seek for nou- 

 rishment. It is not surprising that so long a 

 fast should have thinned it, and rendered it 

 very voracious. At first, therefore, it is not 

 very difficult in the choice of its food ; almost 

 any vegetable that is green seems welcome ; 

 but the succulent plants of the garden are 

 chiefly grateful ; and the various kinds of 

 pulse are, at some seasons, almost wholly de~ 

 stroyed by their numbers. So great is the 



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