THE AMERICAN LOBSTER. 
99 
Yitzou records tlie following observations (197) upon the increase in size and 
weight of molting lobsters. In a lobster which was measured immediately before and 
after the molt it was found that the carapace had gained 11 mm. in length and the 
abdomen 8 mm. The last joint of the right claw was smaller by 3 mm., which is 
explained, first, by the thickness of the chitinous layer in this joint, and, secondly, by 
the almost complete absence of blood in the claw at this time. This is a forced con- 
dition, since if the last joint of the claw were increased in .size it would be next to 
impossible for it to be withdrawn (see pp. 86-87). The same lobster 17 hours after the 
molt showed no increase in size of carapace or abdomen, but the claws had gained from 
12 to 15 mm. in length. No increase in any of these parts was noticed on the third to 
the sixth days following the molt, but there was a gain in weight. 
Table 27. 
Time of observation. 
Weight. 
Increase. 
Grams. 
500 
Grams. 
The day foliowing molt 
610 
100 
Third day following molt 
019 
9 
Fourth day following molt 
642 
23 
Fifth and sixth days following molt 
642 
0 
The following measurements show the increase in various parts of the body after 
the molt. They refer to lobster No. 6, table 24 (compare plates 45a and 45 b ) : 
Table 28. 
Measurements. 
Before 
molt. 
Five days 
after molt. 
Increase. 
Length 
Inches. 
9. 28 
Inches. 
10. 50 
Inches. 
1.22 
Length of carapace 
4. 33 
5. 03 
.70 
Greatest width of carapace 
2.2 
2. 33 
.13 
Length of crushing -chela (propodus) 
4.12 
5. 62 
1. 50 
Width of crushing-chela at base of dactyl.. 
2. 06 
2. 56 
.50 
Length of dactyl 
1. 90 
2. 25 
.35 
Width of dactyl at base 
.72 
1.00 
.28 
Length of small cutting-chela (right) 
4.53 
5. 53 
1 . 00 
Width of small cutting-chela 
1.53 
1.47 
— .06 
Length of dactyl 
2.53 
3. 06 
.53 
Width of dactyl 
.56 
.65 
.09 
