growth. They also vary in the number of eggs which 

 they lay at one time, certain of them only depositing 

 three or four, whilst others bring forth upwards of a 

 hundred. 



M. Bouchard has made some interesting observations 

 on the number of eggs laid at one time, the various 

 months in which they are laid, the time they take to 

 hatch, and the number of months elapsing before the 

 animal arrives at its adult age. From his researches 

 we shall borrow from time to time. 



Mollusca have the power of re-modelling, or mend- 

 ing such portions of their shells which may have been 

 accidentally broken, but not so perfectly but what these 

 places may be instantly recognized. 



Animals inhabiting shells lie dormant during the 

 winter months ; some few, however, are occasionally 

 aroused from their torpour on a warm sunny day. 

 They become inactive about October, and remain more 

 or less so until April. Limneus pereger may occasion- 

 ally be seen moving about actively in the mud whilst 

 the surface of the water is frozen over; and a few warm 

 days have invited the Helix or snail family to search 

 for food, but on the first return of frost they again be- 

 come inactive, closing the aperture of their shells with 

 a glutinous substance. Last year Helix asporsa began 

 to crawl about on the 1st of March, but cold weather 

 returning on the 4th, they again became motionless 

 until near the end of the month. Being in the vale of 

 Aylesbury on the 3d of April, I noticed the following 

 shells abroad near Hartwell House:— Helix pulcbella, 

 Helix carthusiana, Helix rotundata, Azeca tridens,and 

 Bulimus obscurus. On the 5th of April, Helix rufes- 

 cens were seen in great numbers at Tring, in Bucking- 

 hamshire. In this neighbourhood but few water shells 

 were noticed until the second week in April ; and, up to 

 the 23d, I could find none in the Trent, nor could I per 



