72 ECONOMIC ZOOLOGY 



which is very similar to the American form, is said to be lighter in 

 proportion to its length than the latter form. 



As to the age to which lobsters live we have but little data, Herrick 

 (97) thinks one of the giant lobsters may be half a century old. A 

 lo-inch female may be five years or more old. As in the crayfish 

 the female lobster carries at certain seasons, a great mass of eggs 

 with her, glued to the swimmerets on the ventral surface of the ab- 

 domen by a secretion of the oviducts, such a female is known as 

 a u berried" lobster and may carry 10,000 or more eggs. These eggs are 

 carried until they hatch into tiny embryos that swim to the surface and 

 look quite different from the adult lobster. After a long series of molts 

 the growing lobsters gradually take on the adult form and sink to the 

 bottom where they live. This process of molting is general among the 

 Crustacea. Being inclosed in an inelastic chitinous exoskeleton the 

 lobster can grow only by periodically shedding this exoskeleton and then 

 expanding rapidly before the new exoskeleton hardens; the growth at 

 one molt is sometimes surprisingly great. Molting among the adults 

 is most common in the late summer and early fall. The process 

 may take from 5 to 30 minutes or longer and it is generally five or 

 six weeks before the new shell is thoroughly hardened. The Amer- 

 ican lobster breeds biannually, though it is possible that annual broods 

 may sometimes be produced. 



On land the lobster, owing to its weight and relatively weak legs 

 is almost helpless, but in water it crawls about actively on the bottom 

 and swims backward, by flopping its tail, at a remarkable rapid rate; 

 one specimen was seen to swim 25 feet in less than one second. Varia- 

 tions of temperature, food supply, etc., cause the lobster to migrate 

 from shallower to deeper water and back, and even to travel along the 

 coast for some miles. It may hide itself beneath rocks and such things 

 or even dig a burrow in the mud, somewhat after the manner of the 

 crayfish. It is carnivorous in habits and feeds most actively during 

 the warmer seasons. 



In the early days the Indians caught lobsters by spearing them. 

 In Europe they were caught by means of long wooden tongs. The 

 method universally employed at present is by the use of traps or 

 "pots, " built on the plan of the typical rat-trap, with a conical entrance 

 at one or both ends. Traps of this sort have been used in Europe for 

 centuries, being known in Scotland as "lobster creels." They were 



