NEWLY-HAITCHED CRAYFISHES. 43 
fringed, and is continued by longer or shorter thread-like 
pedicles into the coat of the same material which invests 
each egg. It very soon hardens, and then becomes very 
firm and elastic. 
When the young crayfish is ready to be hatched, the egg 
case splits into two moieties, which remain attached, like a 
pair of watch glasses, to the free end of the pedicle of the 
egg (fig. 8, A; ec). The young animal, though very similar 
to the parent, does not quite “resemble it in all respects,” 
as Roesel says. For not only are the first and the last 
pairs of abdominal limbs wanting, while the telson is very 
different from that of the adult; but the ends of the great 
.chelz are sharply pointed and bent down into abruptly in- 
curved hooks, which overlap when the chele are shut (fig. 8, 
B). Hence, when the chele have closed upon anything soft 
enough to allow of the imbedding of these hooks, it is 
very difficult, if not impossible, to open them again. 
Immediately the young are set free, they must instinc- 
tively bury the ends of their forceps in the hardened 
egg-glue which is smeared over the swimmerets, for they 
are all found to be holding on in this manner. They 
exhibit very little movement, and they bear rough 
shaking or handling without becoming detached; in 
consequence, I suppose, of the interlocking of the hooked 
ends of the chelz imbedded in the egg-glue. 
Even after the female has been plunged into alcohol, 
the young remain attached. I have had a female, with 
young affixed in this manner, under observation for five 
