204 
BULLETIN OF THE BUREAU OF FISHERIES. 
at low tide have been taken out of bunches of eelgrass at a depth of a few inches only. 
They frequently dig a shallow hole in the mud under stones, where they can await the 
coming change with greater security from enemies. Fishermen have frequently seen 
a cast shell lying on the bottom and have found a soft lobster near by, protected by a 
rock or bunch of kelp. 
Many of the prawns habitually molt in the early morning while it is yet dark, but 
lobsters which we have kept in aquaria have cast both by day and at night. Consid- 
ering the nocturnal habits of the lobsters, we should expect to find the latter practice 
the commoner in a state of nature. In those captives which Brook (57) observed with 
great care, the shells were cast off in the night time and partially buried. 
Anderton (5) found that the lobsters transported from England to New Zealand 
molted mostly at night, their cast shells being usually seen lying upside down on the 
bottom. The shedders retired to some secluded spot where the water was shallow, and 
appeared vicious upon the approach of intruders. On the 3d of September, says 
Anderton, “a male lobster was seen to be behaving in a very peculiar manner in the 
shallow end of the pond. It would walk alongside the concrete dividing wall for a distance 
of about 5 feet, halt, and then turning round would retrace its steps the same distance 
in the opposite direction. In this manner a rut several inches deep was formed in the 
gravel and at one end of this the lobster scooped out a hole about 4 inches deep and 
12 inches in diameter.” The water had to be temporarily withdrawn from the pond, 
but as soon as permitted to do so this lobster resumed its peculiar walk, and continued 
it through the night and the following day. Molting began at 4.30 p. m. of that day 
and lasted 35 minutes. The lobster at first lay on its side, with its large claws extended 
in a direct line with its body, and later turned on its back when the tail, the last part 
to be withdrawn, was released. The habit of scooping a hole in the gravel was noted 
on several occasions, when the soft lobster was found lying beside its “shadow.” As 
noted in chapter ix, molting in the females was almost immediately followed by copula- 
tion, whenever a male was available, and the interval between this act and the laying 
of the eggs was in two cases observed — 65 days. Molts in both sexes were recorded 
from November 18 to March 3, but rather more frequently in the warm months of Novem- 
ber and December. 
THE MOLTING ACT. 
A male “shedder” was caught in the harbor of Woods Hole July 13 and placed 
in an aquarium. At exactly 2.48 p. m. this lobster began to molt and in 6 minutes 
was out of its shell. 
When the lobster is approaching the critical point the carapace or shell of the back 
gapes away a quarter of an inch or more from the tail. Through the wide chink thus 
formed the flesh can be seen glistening through the old and new cuticle, giving it a 
decidedly pinkish tinge. Take the lobster up in the hand now and the tail drops down 
as in death, the strong muscles which bind the pleon to the carapace being completely 
relaxed. When this stage is reached the time of exuviation is at hand and the process 
becomes purely automatic, the animal having no control over its own movements. 
