504 THE PHILOSOPHY 



ftrengtii. They dig holes in the earth, the moutlis of which 

 they cover with leaves and mud. Here they throw oflf their 

 old ihells, remain quite naked, and almoft without motion 

 for fix days, when they become fo fat that they are efteemed 

 delicious food. When the new fhell has hardened, the ani- 

 mals, by an inftindlive impulfe, march back to thofe moun- 

 tains which they had formerly deferted. In Jamaica, where 

 they are numerous, the land-crabs are regarded as great deli- 

 cacies J and they are fo abundant, that the flaves are often 

 fod entirely upon them. 



The migrating principle is not confined to men, quadru- 

 peds, birds, and reptiles : It extends to many of the infeEl 

 tribes. Numberlefs inhabitants of the air pafs the firfi: fi:ages 

 of their exifirence In the waters. There they remain for 

 longer or (horter periods, according to the fpecies. Previous 

 to their transformation into chryfalids, they quit the waters, 

 and come upon dry ground, where they undergo their amaz- 

 ing change. Infiiead of adlive water -worms, they dig or find 

 holes in the earth, v^here they are converted into chryfalids, 

 or feemingly inanimated beings, and, in a fhort time, mount 

 into the air in the form of winged infecSls. Similar migra- 

 tions are to be obferved among land-infeiTts. But migration 

 is not confined to w^ater-worms. Many fpecies of caterpil- 

 lars which feed upon the leaves of trees, flirubs, and other 

 vegetables, when about to undergo their transformation, 

 leave their former abodes, defcend from the trees, and con- 

 ceal themfelves in the earth. The hiving of bees, when nu- 

 merous colonies remove in order to efiiablllh new fettlements, 

 is another infiiance of the migration of infects. Indeed, if 

 we except bees, wafps, ants, and a few others, mofi: infects, 

 whether they inhabit the air, the earth, or the w^aters, are 

 perfect wanderers, having no fixed place of refidence. Some 

 of them, as the fpider tribes, build temporary apartments ; 



