270 



It may be worth observing, that lobsters use their 

 tails as fins, wherewith they commonly swim back* 

 ward, by jerks or springs, reaching sometimes ten 

 yards at a spring. For this purpose, as the gill.fins 

 of other fishes, which are their oars, are a little con- 

 cave backward, these have the plates of their tails, 

 when they bend them down as they use to do, a little 

 concave for ward. 



Different from all these are the land crabs of the 

 Caribbee islands ; which Jive in a kind of orderly 

 society, within their retreats in the mountains ; and 

 regularly once a year march down to the sea side in a 

 body of some millions. They chuse the months of 

 April and May to begin their expedition : ^and then 

 sally out from the stumps of hollow trees, from the 

 clefts of rocks, and from the holes which they dig for 

 themselves under the surface of the earth. At that 

 time the whole ground is covered with this band of 

 adventurers. The sea is their place of destination, 

 and to that they direct their march. No geometrician 

 could send them to their destined station, by a shorter 

 course. They never turn to the right or left, what- 

 ever obstacles intervene, And evenif they meet with 

 a house, they will attempt to scale the walls, to keep 

 the unbroken tenor of their way. But upon some oe 

 casions they are compelled to conform to the face of 

 the country ; and if it be intersected by rivers, they 

 wind along the course of the stream. They are com. 

 inonly divided into three battalions; of which, the first 

 consists of the strongest and boldest males, that like 

 pioneers, march forward to clear the route, and face 

 the greatest dangers. These are often obliged to halt 

 for want of rain, and wait till the weather changes. The 

 main body of the army is composed of females, which 

 never leave the mountains till the rain is set in, and 

 then descend in regular battalia, in columns of fifty 

 paces broad, and three miles deep, and so close, that 

 they almost cover the ground. Three or lour days 

 after this, the rear-guard follows ; a straggling undis- 



