164 CONCHOLOGIST’S COMPANION. 
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 him to discover that the pulsations of the 
heart succeeded each other at intervals of three 
seconds. A casual observer might be inclined to 
pity the poor animal for the deficiency of its 
moving powers. But let it not be forgotten, that 
this defect of the Helix is amply compensated.— 
The peculiar nature of its juices seems to have a 
reference to its mode of life; for no degree of 
natural, or artificial cold, has ever been known 
sufficiently powerful to congeal them. Thus, while 
the common worm, which incautiously has left its 
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 
till invited from his temporary retreat. Appian 
beautifully notices the creeping movements of this 
curious little animal, in the following characteristic 
lines :— i 
«* When lov’d Arcturus leaves the main to rise 
A star, bright shining in the evening skies, 
Then prune the vine; *t is dangerous to delay, 
Till with complaints the swallow breaks the day ; 
When with their domes the slow-paced snails retreat 
Beneath some foliage, from the burning heat.”’ 
