HATCHING OF EGGS 43 



477. These eggs weighed 624 to the ounce, and, in excluding 

 the batch of 246, B parted with | of its own weight in 40 hours, 

 while the whole number laid were rather over | of its own 

 weight ! 



While depositing the eggs, the slug remained throughout in 

 the same position on the surface of the ground, with the head 

 drawn up underneath the mantle, which was lifted just above 

 the reproductive orifice. When taken into the hand, it went on 

 la3dng eggs without interruption or agitation of any kind. After 

 it had finished laying it ate half a raw potato and then took a 

 bath, remaining submerged for more than an hour. Bathing is 

 a favourite pastime at all periods. Specimens, says Mr. Wotton, 

 have survived a compulsory bath, with total submersion, of 

 nearly three days' duration. 



Mr. Wotton's account of the hatching of the eggs is equally 

 interesting. It is noticeable that the eggs of one batch do not 

 hatch by any means simultaneously; several days frequently 

 intervene. The average period is about 60 days, a damp and 

 warm situation bringing out the young in 40 days, while cold 

 and dryness extended the time to 74 days, extremes of any kind 

 proving fatal. Of the batch of eggs laid by B on 30th Novem- 

 ber, the first 2 were hatched on the following 16th January, 

 and 2 more on the 17th ; others, from 10 to 20, followed suit 

 on the succeeding 5 days, until 82 in all were hatched, the 

 remaining 19 being unproductive.^ 



By placing the egg on a looking-glass the act of exclusion 

 can be perfectly observed. For several days the inmate can be 

 seen in motion, until at last a small crack appears in the surface 

 of the shell : this gradually enlarges, until the baby slug is able 

 to crawl out, although it not unfrequently backs into the shell 

 again, as if unwilling to risk itself in the world. When it once 

 begins to crawl freely, it buries itself in the ground for 4 or 5 

 days without food, after which time it emerges, nearly double 

 its original size. At exclusion, the average length is 9 mm., 

 increasing to bQ mm. after the end of 5 months. Full growth 

 is attained about the middle of the second year, and nearly all 

 die at the end of this year or the beginning of the next. Death 

 from exhaustion frequently occurs after parturition. Death 



1 I succeeded in hatching out eggs of Helix aspersa, during the very warm 

 summer of 1893, in 17 days. 



