gain: food and habits of slugs and snails. 57 



of about seventy eggs within half-an-inch of the first; the animal had 

 been isolated. It is probable that a single impregnation, which 

 generally takes place in June or July, is sufficient to fertilise two, or 

 perhaps more, batches of eggs deposited at intervals during the 

 period the animals are active. 



This explains a circumstance which has hitherto greatly puzzled 

 me. I will first give the life of a Helix aspersa, from the egg to its 

 death, presumably from old age. 



Some eggs were accidentally introduced with earth placed in a 

 flower-pot in which I kept some H canHana\ the eggs hatched 

 about August 1882. Three attained a diameter of three-eighths of 

 an inch before winter, and one lived through the winter, fed on colt's- 

 foot and cabbage. On the 5th October, 1883, it was just one inch 

 in diameter, lip not formed, though there was a slight thickening of 

 the rim of the shell. July 1884 — shell finished ; diameter, including 

 a very well finished lip, one inch and an eighth. May 3rd, 1885 — 

 left winter-quarters and became active ; soon after, I introduced a 

 companion with which I saw it in company on August 5th. On the 

 9th it deposited eggs in the soil ; shell nearly covered the whole day. 

 September 10th — some small shells beneath the surface. On the 

 17th the young were feeding; on the 24th two of the clutch had 

 increased in size, the remainder died off. In the middle of May 

 1886 the largest of the young had attained a size of eleven-sixteenths 

 of an inch. On the 13th October, T887, the old snail was found 

 dead, having lived five years and two months. 



The circumstance to which I alluded is this : — Soon after the 

 eggs were hatched in September 1885, I removed the companion 

 which I had introduced, leaving the snail with a H. pomatia, some 

 H. nemoralis, etc. Early the following summer a large brood 

 appeared, which I hoped were a cross between Jf. aspersa and 

 H. pomatia, and of course I watched them with great interest — only 

 to find they were pure H. aspersa. Now I have no doubt these were 

 the product of the first conjunction which I witnessed, but whether 

 the eggs were deposited the following summer, or remained unhatched 

 during the winter, or hatched and remained beneath the soil, cannot 

 now be determined. That the last-named might have occurred is 

 probable, as very small Helices, etc., are to be found hybernating 

 plentifully under leaves in woods. 



In the summer of 1885 I received four full-grown examples of 

 H. pomatia. Saw a pair in copulation on 15th July. On the 6th of 

 August I found the young, about the size of peas, an inch below the 

 surface of the sandy soil placed in a moderately large box, fitted 

 with a glazed cover, in which the animals were kept. On the 17th 



Feb. 1889. 



