50O THE PHILOSOPHY 



Of the land-crab there are feveral fpecies. The migration of what 

 is called the violet land-crab deferves fome notice. It inhabits the 

 warmer regions of Europe : But its particular refidence is in the 

 tropical climates of Africa and America. Land-crabs generally fre- 

 quent the mountainous parts of the country, which are, of courfe, 

 moft remote, from the fea. They inhabit the hollows of old trees, 

 the clefts of rocks, and holes which they themfelves dig in the earth. 

 They are extremely numerous. In the months of April and May, 

 they leave their retreats in the mountains, and march in millions to 

 the fea-fhore. At this period the whole ground is covered with 

 them ; and a man can hardly put down his foot without treading 

 on them *. The objedl of their migration is to depofit their fpawn 

 on the fea-fhore. In their progrefs towards the fea, like the nor- 

 thern rats, the land-crabs move in a ftraight line. Even when a 

 houfe intervenes, inftead of deviating to the right or left, they at- 

 tempt to fcale the walls. But, when they meet with a river, they 

 are obliged to wind along the courfe of the ftream. In their mi- 

 gration from the mountains, they obferve the greateft regularity, 

 and commonly divide into three battalions or bodies. The firft con- 

 fifts of the flrongeft and boldeft males, who, like pioneers, march 

 forward to clear the route, and to face the greateft dangers. The 

 females, who form the main body, defcend from the mountains in 

 regular columns, which are fifty paces broad, three miles long, and 

 fo clofe that they almoft entirely cover the ground. Three or four 

 days afterwards, the rear-guard follows, which confifts of a ftrag- 

 gling undifciplined troop of males and females. They travel chief- 

 ly during the night ; but, if it rains by day, (for moifture facilitates 

 their motion), they proceed in their flow uniform manner. When 

 the fun fliines, and the furface of the ground is dry, they make an 

 univerfal halt till the evening, and then refurae their march. When 



alarmed 



* Voyage aux Ifles Francoifes par Labat, torn. 2. pag. 221. 



