3 1 8 Shell Life 



shell is thin, semi-transparent, yellow-brown, with 

 a large oval mouth. This is the Poncl-snail that 

 everybody knows, because it is ubiquitous wherever 

 there is slow or stagnant water. Sometimes it 

 turns up at some distance from the water in damp 

 meadows, and has even been detected climbing 

 willow - trees. Like L. stagnalis, the Wandering 

 Snail is liable to great variation, dependent no doubt 

 on the area of the pond, the chemical character and 

 temperature of the water, the quantity and quality 

 of food available. Some of these varieties differ 

 considerably from the type. It is a restless creature 

 when in the water, always on the move, but out of 

 the water, where it spends a good deal of time, it is 

 usually very quiet, being then mainly concerned with 

 the fabrication and hardening of additions to its shell. 

 Like L. stagnalis it declines to be restricted in its 

 diet, even practising cannibalism when overcrowded. 

 It may be seen industriously assisting in the dissolu- 

 tion of a superfluous dog that has been consigned to 

 the waters attached to a brick. When drought comes 

 they protect themselves by burial to a depth of 

 several inches in the mud whilst it is still soft. A 

 thick coating of ice on the pond does not stop their 

 activity below, and they may even be frozen in solid 

 ice, apparently, without prejudice to their vitality. 

 It is very prolific, as may be gathered from its 

 abundance, and it is estimated that each individual 

 produces about 1300 eggs in one season. These are 

 deposited in cylindrical masses of clear jelly. The 

 shell in the numerous forms varies from half to one 

 incli in length. 



The Glutinous Snail {AmiMpeplea glutmosa) is 



