80 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



these eggs ran/ in an arithmetical .scries. According to this law we should -have the 

 following: 



Lengths (in inches) 8 10 12 14 16 



Numbers of eggs 5,000 10.000 20,000 40.000 80,000 



Aii examination of nearly a thousand cases shows that the first three terms of 

 these series express very closely what actually occurs in nature. The data are not 

 sufficient for carefully testing the fourth and fifth terms, but the largest number of 

 eggs obtained suggests that there is a tendency to maintain this high standard of 

 production, even at an advanced stage of sexual life. I believe that the law formu- 

 lated above expresses very nearly the propagative powers of the lobster during the 

 height of its sexual activity, though it is not to be supposed that the latter conforms 

 uniformly to any arithmetical standard. 



Fertilization is effected on the outside of the body of the females by means of sperm 

 cells which the male discharges during copulation into a seminal receptacle. This is 

 situated on the under surface of the female, on the middle line, between the basal seg- 

 ments of the third pair of walking legs (fourth pair of pereiopods) and may be opened 

 with a knife by pressing the elastic sides of its median aperture. The peculiar grooved 

 legs of the first segment of the tail of the male are probably inserted into this pouch in 

 copulation, but nothing is definitely known of the process. The spermatozoa are dis- 

 charged in masses, embedded in a translucent jelly, which is secreted in the glandular 

 section of the seminal duct (by spermatophoral glands). These packages of sperm cells 

 are the spermatophores. The sperm cells of the lobster, when they leave the testis, 

 are provided with three long, slender processes, which radiate from the constricted 

 neck of the cell and are perfectly rigid. It is possible that the function of these pro- 

 cesses is to hold the sperm cells together in masses, in the spermatophores, until they 

 are deposited in the seminal receptacle. Here the sperinatophores become disorgan- 

 ized, and the sperm may then be easily pressed out in a semifluid, grayish mass. The 

 rigid processes, which would be an impediment to the translation of the sperm, have 

 become relaxed, bent up. and in some cases have disappeared. The way in which the 

 spermatozoa reach and penetrate the eggshell and cooperate in fertilization is 

 unknown. 



A female lobster, which laid her eggs -Inly 1, 1890, was kept under observation at 

 the Fish Commission station at Woods Holl 335 days, until June 1, 1891, when the 

 eggs had begun to hatch. The hatching of the eggs begins there in May and extends 

 into July, but the greatest number are invariably hatched in June. I am informed by 

 Mr. Nielsen, superintendent of fisheries in Newfoundland, that the eggs are laid there 

 from the first week in August to the latter part of September,* and that the greater 

 number are hatched from the 15th or 20th of July to the 20th of August. He also states 

 that he has hatched some eggs in floating incubators as late as November. 



On the southern section of the coast of Massachusetts the eggs are laid in June, 

 July, and August. In some seasons the greater number are extruded during the latter 

 part of June and the first part of .Inly, in others in the last of July and the first of 



*In the Annual Report of the Newfoundland Fisheries Commission for 1892, Mr. Nielsen states 

 that "the principal spawning time of the lobster, in Newfoundland waters, extends over a. period of 

 from 25 to 30 days, from the 20th and 25th of July to the 20th of August," and also that "the ova on 

 the majority of the berried lobsters do not begin to hatch in any considerable numbers before the first 

 week in August.'" 



