PULMONATA. 3 



mating influence of the sunshine. Whether these meetings serve 

 any useful purpose in the economy of the animal, or are caused 

 by the pleasurable sensation, and renewed strength derived from 

 the warmth of the situation after the debility of their winter's 

 torpidity, is uncertain ; it is probable, however, that they precede 

 the business of procreation. It is certain that they last but a 

 short time, and that after early spring, the animals are to be 

 found in their usual retreats. 



In the course of the months of May or June, earlier or later, 

 according to the locality and as the season is more or less warm, 

 they begin to lay their eggs. These are deposited, to the 

 number of from thirty to fifty and even more, in the moist and 

 light mould, sheltered from the sun's rays by leaves, or at the side 

 of logs and stones, without any order, and slightly agglutinated 

 together. The depth of the deposit is usually measured by the 

 extreme length of the animal, which thrusts its head and body 

 into the soil to the utmost extent, while the shell remains at the 

 surface ; but sometimes the animal burrows three or four inches 

 deep before making the deposit, in order to insure a sufficiently 

 moist position. Three or four such deposits, and sometimes 

 more, are made by one animal during the summer and autumn. 

 When the deposit is complete it is abandoned by the animal. 

 The eggs vary in size according to the magnitude of the species 

 producing them. They are nearly globular, one axis being some- 

 what longer than the other, white and opaque. They consist, in 

 general, of an external, semi-calcareous, elastic membrane in- 

 vesting the whole, the interior surface of which is usually studded 

 with numerous rhombic, microscopic crystals of carbonate of lime, 

 some species however having a hard enveloping calcareous shell, 

 of the consistence of that of a bird's egg ; of an inner thin, trans- 

 parent, shining membrane which immediately incloses a trans- 

 parent and somewhat viscid fluid, analogous to the albumen of 

 bird's eggs ; of the albumen itself, and of the vitellus, which, 

 possessing the same degree of transparency as the albumen, 

 cannot be distinguished from it at this time. The elastic eggs 

 when first laid are often flaccid, and seemingly only half full of 

 fluid, but they soon absorb moisture and become distended. The 

 embryo animal, with its shell, is observable in the albuminous 

 fluid in a few days after the egg is laid. Its exclusion takes 

 place, under ordinary circumstances, in from twenty to thirty 



