266 Miscellaneous. 
twenty-five days; so that the young animal changes its eut 
Jive times in from ninety to one hundred days, eigen gee) 
months of July, August, and September. From the end o f this last 
the end of April in the following year there is no 
change. 
The sixth moult takes place in May, the seventh in J une, and the 
eighth in July. ‘there are consequently eight moults in the first 
twelve iha of the life of the young crayfis 
n the second year there are five moults :—the first and second in 
pp and September; the third, fourth, and fifth in May, June, 
and July. 
In the third year I have observed only two i of which the 
first takes place in July and tke second in September. From this 
time the young crayfish becomes adult, on entering upon its fourth 
en the crayfish are adult, moulting takes place only once a 
year in the females ; it occurs, boncum: twice in the males, which 
explains why the latter are larger than the females, the growth 
being in proportion to the number of moults. In the adult males 
first moult takes place in June and July, and the second in 
August or September. The single moult of the females occurs in 
Side or Septem 
effect its moult, the animal places quus on its side; with its 
head and back it raises its carapace, which swings like a li d upon its 
hinge; then, when it has thus completely disengaged the anterior 
part of its body, it separates entirely from its old carapace by a 
sudden movement of the posterior part. This operation, which lasts 
about ten minutes, is favoured by the previous secretion of a gelati- 
nous Ha between the two earapaces, which facilitates their 
rgage 
Twelve hc eid after the nk the legs of the crayfish are already 
sufficiently firm to pinch strongly; twenty-four hours afterwards 
they are completely hardened. The walls of the back remain longer 
flexible; but at the end of m hours they have attained nearly 
an gree of consistenc 
The young animals remain abed to the false legs of the mother 
for ten days after exclusion, when the first moult takes place; this 
is effected actually under the tail of the mother*. Uu tbe young 
, detach themselves before this period, they cannot live separately ; 
but after this first moult they sometimes quit their mother and re- 
turn to her again, up to the twentieth dey, at which period they 
ean live independently. 
* Note by M.C. Robin.—I have ascertained, by means of the microscope, 
as shown by M. Chantran to the Academy, "that the e young remain sus- 
pended beneath the abdomen of the mother by means of a hyaline chiti- 
membranous ome na of the caudal appendage. This flament exists when 
the e only attained about three fourths of their mp 
before a bera 
