NATURAL HISTORY OP AMERICAN LOBSTER. 
293 
the reproductive functions are apt to be disturbed. The eggs, instead of being expelled 
in the natural way, perish in the ovary, possibly by having their requisite supply of 
oxygen from the blood curtailed, and absorption of this inert mass begins, in part at 
least, through the agency of the blood. By taking up the green pigment from the eggs 
the blood becomes very dark in color, thus giving all the tissues an unpalatable greenish- 
black appearance, very noticeable at the articular membranes. 
The green color of the eggs, like that of all parts of the integument of this animal, 
is due, as we have seen, to the presence of dissolved pigments of a very unstable char- 
acter. In consequence of partial absorption and coincident changes in the pigment 
which remains, the degenerating eggs gradually assume a yellowish-orange color. 
Whether the animal survives these conditions and succeeds in producing another batch 
of fertile eggs in due course has not been determined, but the chances would seem to 
be wholly in its favor. 
While physiological disturbances of this kind are commonly induced by unnatural 
conditions, a single case has been observed in which the eggs of an animal recently 
taken from the sea were partially absorbed. Degeneration had spread irregularly 
throughout the entire organ, which at this stage of the process presented a remarkable 
appearance, being dark green, marbled with light lemon yellow. All the tissues 
pervaded by the blood seemed to be steeped in a green dye, which the organism was 
trying to throw off. 
The structure of the ovaries, as outlined, suggest certain questions of considerable 
economic interest, such as the age at which sexual maturity is reached, the limits of 
the breeding season, and the length of the reproductive cycle or the frequency of 
spawning. We shall endeavor to show what light direct observation and anatomy have 
shed upon these matters. 
PERIOD OF ADULT LIFE OR SEXUAL MATURITY. 
The age of sexual maturity varies greatly in individuals, extending over an interval 
in which lobsters vary in length from 7 to 11^2 or 12 inches. Out of thousands we 
should expect to find here and there one of possibly less than 7 and more than 12 inches 
in length coming to maturity for the first time. We may safely conclude that the 
majority of these animals are mature when inches long. Very few are with spawn 
before attaining a length of 8 yi or 9 inches. In order to test this question traps must 
be put down at a certain point, kept there for a long period, and the catch noted day 
by day and month after month. This was done in the harbor at Woods Hole, Mass., 
where traps were laid by Mr. Vinal Edwards December 1, 1893, and the daily catches 
recorded until July 1, 1894, the conditions as to molting and the presence of eggs being 
noted in each individual. A summary of the catch showing the proportion of each 
sex and the presence of external eggs is recorded in table 9. During a period of 6 months 
1,344 female lobsters were captured, and of these 168 carried eggs; of 249 females 
measuring from 6 to 8 inches but 3 bore eggs, while of those under the 9-inch length 
but 1 1 were berried. 
