REPORT OF COMMISSIONER OF FISH AND FISHERIES. 163 



laid from June 20 to July 15, iind probably later; and in 1800, from 

 July 1 until about August 20, according- to the observations made. 

 Lobsters do not breed readily when confined in close quarters. One 

 female kept in a small aquarium for about ciglit weeks extruded eggs 

 which were somewhat abnormal in their condition, and in the course 

 of a few days they* were scratched off by her from the swimmerets. 

 The hatching period at Woods Holl occupies al)out eight weeks, be- 

 ginning about the middle of May and continuing nntil near the middle 

 of July, but it varies somewhat. In 1800 the last 16bster with light- 

 colored spawn (about ready to hatch) was taken July 7, and on the 

 same day the Gay Head tishermeu obtained the first lobster of the 

 season with dark-colored or newly laid eggs. 



Prof. Herrick considers that the lobster does not breed annually, 

 judging from the immature condition of the ovaries at the time of hatch- 

 ing of the eggs attached to the swimmerets, and by the large percent- 

 age of non-egg-bearing females taken in the winter and spring. In 

 April, 1880, 21 per cent of all the lobsters caught at Woods Holl by 

 Mr. Edwards were females with eggs; in May, 10 per cent, and in 

 June only ab(^ut one-half of 1 i)er cent, the larger proportion of the 

 eggs having hatched previous to, or during the early part of, the last- 

 mentioned month. In the course of these observations it was also 

 noticed that the females somewhat exceeded the males in numbers. 



Freshly laid eggs are very dark green in color, but toward the next 

 sju-ing they become much lighter, owing to the partial consumj^tion of 

 the 3'olk. The adult lobster may molt soon after its eggs are hatched 

 (most commonly in the early summer) or not until fall, and possibly at 

 anyother time when not carrying eggs. The frequency of the fall 

 molting has been referred tQ elseAvhere. Prof. Herrick is inclined to 

 think that, after becoming sexually mature, lobsters do not, as a rule, 

 molt annually. From six to eight weeks are probably required to pro- 

 duce a fairly hard new shell. At the time of hatching the larval lobster 

 also molts for the first time, the delicate skin being cast oft" with the 

 shell. This is a critical period in its history, and in connection with 

 the work at Woods Holl large numbers die at this stage through ina- 

 bility to pass the first molt. The young swim at the surface for six or 

 eight weeks, Avhen they attain a stage which bears a general resemb- 

 lance to the adult, althougii d ifforing from it in many details. The larva 

 at this age both walks on the bottom and SAvims at the surface, but when 

 it reaches the next stage, it leaves the surface entirely. 



During the early spring of 1800, Prof. Bumpus succeeded in hatch- 

 ing lobster eggs prematurely by placing them in running water, of 

 wliich the temperature had been elevated artificially to that of the sea 

 water in June. The young made their api)earance in a very few days. 

 Other eggs from the same lobster retained in water of normal temper- 

 ature did not devehq) api^rcciably during the same period. The young 

 produced in this way seemed strong and hardy and no fatal results 



