THE REPRODUCTIVE PERIOD IN THE LOBSTER. 
165 
were placed in a floating box in summer time. When their ova had all hatched out 
these females were kept confined with two males until after October 1-1, when one 
was found to have newly spawned. This proves that it is possible for the European 
lobster to spawn in two successive years, but it does not prove that this is the com- 
mon habit of the species. It also strongly suggests that these October eggs corre- 
spond to the “fall” and “winter” eggs occasionally produced in the American 
form. By accelerated growth of the ovary, eggs might be laid in fall or winter 
when not normally due until the summer following. Under such circumstances the 
ovarian eggs would come to maturity in fifteen instead of twenty-three months. It 
would be interesting to know when these fall eggs hatch. As already suggested, it is 
possible that they do not give rise to the regular summer broods. In the American 
species hatching of larva? has been casually detected in November and January. 
Professor Prince, who rejects the idea of a biennial spawning period, expresses 
surprise that the notion first advanced by persons wholly untrained and unqualified 
to form a reliable judgment has received support recently from men of scientific 
standing. A statement of mine is given a construction which might seem to support 
the idea that eggs are laid in consecutive years. Thus he says that I found in paper- 
shell lobsters in July that just after the brood had hatched and the molting was over 
the eggs in the ovaries were no less than half the size of mature ova. I speak of the 
diameter of these ova which, if by size is implied their volume, is quite a different 
matter.* 
Again, it is said that I do “ not hesitate to affirm concerning this supposed bien- 
nial spawning that to prove it requires only the dissection of a female ivith eggs 
ready to hatch in June, July, or August, and it will be found that “the ovarian 
eggs have had, in all these cases, from ten months’ to a year’s growth” — the very 
point, in fact, being assumed which requires proof.” It would be a work of superero- 
gation to go over in detail this ground again, but I can reaffirm the statement with 
added emphasis. That the majority of female lobsters which spawn in summer carry 
their eggs attached to the swimmerets until these same eg'gs hatch ten or eleven months 
later is a proved and settled fact admitting of no doubt. It was proved at Woods 
Hole, and the same experiment was conducted on a large scale by Mr. 11. P. Green- 
leaf, at Southport, Me. f In July and August, 1892, he placed 300 egg lobsters 
in a pound at that place. In April, 1893, he seined and found the females still carry- 
ing their eggs; again, he seined the pound in June, when most of the eg’gs were 
hatched. Moreover, I have determined the rate of growth of the external eggs from 
actual observation, from the time of extrusion to hatching. The external summer 
eggs are a pei’fect chronometer for measuring the rate of growth of the ovary during 
the first period — that is, during the fall, winter, and spring following any given 
ovulation. 
“The fact,” says Prince, “that the lobster spawns annually is evidenced by: 
(1) The fairly uniform proportion of ‘berried’ females taken season after season. 
(2) The occurrence of the berried conditions in all sizes of females from 7 inches to 18 
inches. It might be expected that females of certain specified sizes would never or 
rarely be found with eggs were biennial spawning a fact. (3) Exact researches upon 
*Ibid, p. 152. 
•jTbid, p. 58. 
