CRUSTACEA. 129 



tropical parts of America, Asia, and Africa. During 

 the day they hide themselves in damp holes or 

 cavities of trees and rocks, or lie motionless under 

 damp blocks of stone. Although, like fish and 

 other Crustacea, etc., they are furnished with 

 branchiae or gills for breathing, they cannot live in 

 the water. At certain periods of the year, generally 

 about the month of May, they unite in troops, and 

 make long excursions over the country towards the 

 sea, where they repair to lay their eggs. Thus 

 once a year they march down to the sea-beach, 

 some thousands at a time, laying waste every- 

 thing they meet on the road. They proceed in so 

 direct a line, that no geometrician could send them 

 to their destination by a shorter course. They 

 travel by night and repose by day, unless it happen 

 to rain, when they profit by the circumstance, and 

 proceed by day also. 



On arriving at the sea- shore, their eggs are 

 deposited in the water, and the mother crabs, 

 leaving accident to bring them to maturity, wander 

 back to their accustomed haunts. About two-thirds 

 of these eggs are immediately devoured by shoals of 

 fish, brought, as it were by instinct, at this particular 

 time to the shore. The young Gecarcini that escape 

 are hatched upon the sand, and soon after millions 

 of these little creatures are seen quitting the shore, 

 and slowly travelling up to the woody mountains. 



