COMMON SNAIL. 177 



fact, since the snail is light, and small, and apparently by 

 no means incapable of comparatively rapid motion ? Doubt- 

 less by the \\iscous nature of his juices, which are extremely 

 tardy in their circulation, and consequently produce a con- 

 siderable degree of sluggishness in the movements of the 

 animal. This idea was first suggested by Mr. Braidley. 

 He observed their circulation in a snail just hatched, the 

 body and shell of which, being quite transparent, enabled 

 liim to discover that the pulsations of the heart succeeded 

 each other at the distance of three seconds. 



A casual observer might be inclined to pity the poor 

 creature for the deficiency of his moving powers. But let it 

 not be forgotten that the defect of the Helix, in this respect, 

 is amply compensated. — The peculiar nature of his juices 

 seems to have a reference to its mode of life ; for no degree 

 of natural or artificial cold has ever been known sufiiciently 

 powerful to congeal them. Thus, while the common worm, 

 which incautiously has left his shelter in the garden mould, 

 is frequently discovered in a frozen state, and even birds 

 and small animals fall victims to the severity of the weather, 

 the snail is rendered insensible to cold, and either burrows 

 in the earth, or seeks the shelter of some hollow tree, til] 

 invited from his subterraneous dormitory. 



