288 NATURAL HISTORY. [cH. XXI. 



caping a thousand dangers, they arrive at the coast, 

 the females immediately prepare to cast their spawn ; 

 this, at first, is seen beneath the tail of the crab, 

 like the spawn of the lobster ; but the crab, seeking 

 the shore, casts off this spawn into the water, 

 leaving it to hatch at random. The 'eggs which 

 escape from the ravenous fishes which attend the 

 arrival of the army, for the purpose of sharing in 

 the annual banquet afforded by the eggs, are soon 

 hatched in the sand, and shortly afterward millions 

 of little crabs are seen quitting the shore, and slow- 

 ly ascending the mountains. The old crabs have 

 much less energy, and do not return until they have 

 cast their skins, and obtained a new and hardened 

 coat. 



The Hermit-crab (Pagurus Bernhardus) is a com- 

 mon British species, which exhibits in its economy 

 one of those interesting intimacies of connexion 

 which are so universally found to exist between the 

 structure and habits of animals. Unlike the ma- 

 jority of crabs, the tail of this species is quite 

 fleshy ; if exposed, therefore, the animal would be 

 found to possess no sufficient defence against any 

 accident which might happen to it in the tempestu- 

 ous element in which it resides, against those 

 species of fish and other marine animals which 

 would devour it. Hence nature has directed it to 

 take refuge in the deserted shells of various mollus- 

 cous animals, which it seems to select almost in- 

 discriminately according to its size, from the small- 

 est nerite to the largest whelk. Having the hinder- 

 part of its body introduced within this shell (which 

 it accommodates to its wants in a remarkable man- 

 ner), it may be seen crawling about with much 

 agility, thrusting out its larger claw to seize upon 

 its food, and with which it is unable to pinch very 

 hard. It is curious to watch the manoeuvres of this 

 crab when its old house has become too small for it, 

 and it is in search of a new one. Crawling slowly 



