of the Fishery Board for Scotland. 



108 



lobster the larger the number of eggs which it carried. A lobster 10 

 inches long had 8000 eggs, while one 15 inches in length bore 32,000. 

 Herrick found in the American lobster that the number of eggs varied 

 from 3000 to 70,000. The eggs of two lobsters were estimated at the 

 Laboratory in the following manner : — They were snipped off the 

 swimmerets and dried in a water-bath. A small portion was detached 

 and weighed, the number of eggs in it was counted, and the total 

 number was got from the total weight. One measuring 11^ inches in length, 

 11,300 eggs, while the other, 12^ inches long, had the same number. 



It is remarkable that so small a number of fry was obtained from the 

 parent lobsters kept in the Bay of Nigg. This is partly accounted for 

 from the fact that a greater or less quantity of the eggs is lost when the 

 berried hens are handled, and during transport. This does not, however, 

 seem sufficient to account for the whole of the shortage. 



Hatching. 



Hatching occurred at the Laboratory during July, August, and Sep- 

 tember. The earliest larvae appeared about the middle of July, the 

 majority hatched in August, and a few in September. 



According to Coste* hatching takes place in March, April, and May. 

 Allen records that hatching took place in one instance in March. Fabre- 

 Domergue, and Bietrix t observed the hatching of the lobster, and 

 describe the process in detail. The larvae issue early in the night. 



The whole brood of any one female does not hatch out at once, but 

 over a period, the larvae issuing in two or more batches (vide Coste, Herrick, 

 and Fullarton). The incubation period, according to Ehrenbaum, Herrick, 

 and Fullarton, is about eleven months. During an incubation period so 

 extended it is to be expected that a certain variation will have occurred 

 in the point of development readied by different eggs. This would result 

 in spreading the hatching of the eggs over a period which probably does 

 not usually exceed a fortnight or three weeks. The first larval lobsters 

 were observed on July 11th, and one of the females was found to have 

 hatched all her eggs on August 2nd. The larvae usually appeared in 

 the morning. 



Measurements of the Lobster. 



Occasionally lobsters are measured by the length of their barrels, i.e. of 

 the carapace, from the extremity of the rostrum to the hind border. In 

 several cases the relation between the total length and the length of the 

 barrel has been noted, and the data are entered below. 



Total Length of Lobster, 



Length of Barrel. 



5 9^ inches. 



2 log „ 

 $ 11 „ 

 $ 1H „ 

 12* „ 

 d 13 



4^ inches. 

 44 



K 1 



°T6 " 



°2 55 

 K5 



°8 »5 



* Vide Buckland. 



t Fish Trades Gazette, Sept. 26. 1903. 



