THE REPRODUCTION OF LIMBS. 37 
fluttered about in the greatest agitation. He was quite 
soft ; and every time I entered the room during the next 
two days, he exhibited the wildest terror. On the third, 
he appeared to gain confidence, and ventured to use his 
nippers, though with some timidity, and he was not yet 
quite so hard as he had been. In about a week, how- 
ever, he became bolder than ever; his weapons were 
sharper, and he appeared stronger, and a nip from him 
was no joke. He lived in all about two years, during 
which time his food was a very few worms at very uncer- 
tain times ; perhaps he did not get fifty altogether.” * 
It would appear, from the best observations that have 
yet been made, that the young crayfish exuviate two or 
three times in the course of the first year; and that, 
afterwards, the process is annual, and takes place usually 
about midsummer. There is reason to suppose that very 
old crayfish do not exuviate every year. 
It has been stated that, in the course of its violent 
efforts to extract its limbs from the cast-off exoskeleton, 
the crayfish sometimes loses one or other of them; the 
limb giving way, and the greater part, or the whole, of it 
remaining in the exuvie. But it is not only in this way 
that crayfishes part with their limbs. At all times, if the 
animal is held by one of its pincers, so that it cannot 
get away, it is apt to solve the difficulty by casting off 
* The late Mr. Robert Ball, of Dublin, in Bell’s “ British Crustacea,” 
p. 239. 
