206 
BULLETIN OF THE BLTREAU OF FISHERIES. 
reproduced in the new one, but in the latter the fringes of stiff setae are as soft as silk, 
the stony ends of the claws, the rostrum, and every spine of the body so soft as easily 
to bend beneath the finger. Possibly the hardest parts of the newly molted lobster are 
the horny surfaces of the teeth of the stomach sac. The large claws are considerably 
distorted, as well as some of the other parts, being compressed and drawn out to an 
unnatural length. After getting clear of the old shell the animal is not inclined to 
activity. It soon orients itself, however, resting in the usual way, and is capable of 
moving about with some degree of agility by the flexure of the tail. Fishermen who 
have had lobsters shed in their cars or traps have often been surprised by the ease with 
which they sometimes slip through their fingers. 
The length of the cast shell of this lobster was x i .25 inches, and shortly after the molt 
the animal measured 12 inches from tip to tip. On July 17, four days after molting, 
the length was a little short of 12.5 inches. The increase in length was thus very 
nearly 1.25 inches. Very soon after molting the lobster is ready to take food, the body 
plumps out to its natural shape, and no further increase in volume can take place until 
another molt. 
The increase in length of body at each molt in lobsters between 5.5 and 11.5 inches 
is between 11 and 12 per cent. Increase in length diminishes beyond this period, yet 
the volumetric increase of the entire body, especially the big claws, may be as great 
or even greater. Beyond the twenty-second stage, according to Hadley, the male 
grows more rapidly than the female. 
WITHDRAWAL OF THE BIG CLAWS. 
The shell of the large claw is molted entire without a rupture in any part. This 
means that the great mass of muscles which fill its terminal joints must undergo disten- 
tion and compression to an extraordinary degree, since it is all drawn through the con- 
stricted base of the limb as wire is pulled through the holes of a drawplate. What 
this implies will be best appreciated when it is realized that the cross sectional area of 
the biggest part of the cheliped is more than four times greater than that at its nar- 
rowest point, in the second joint. 
The lobster is aided in accomplishing this feat by the elasticity of the muscles and 
other tissues and by the removal of blood from the fine meat of the claw (pi. xl, and 
fig. 3, pi. xlvi), as well as by the development of absorption areas in the shell of the 
third and fourth segments of the cheliped. (PI. xxxvn, fig. 2, abs. a.) The muscles 
of the big claw, which are pulled out like a stick of candy, are at first quite tense. 
Very soon, however, they relax and, filling with blood and presumably taking up some 
water, they assume their natural form, with proportional increase in size. The absorp- 
tion areas, from which mineral matter is removed preparatory to the molt, are easily 
distinguished in the hard-shell lobster, though less clearly defined. The shell of the 
basal joint becomes a slender ring, but does not break. 
At the time of the casting of the shell the large claws must be practically free from 
blood, since, as Vitzou has pointed out, if the claw were to be increased in size it would 
