THE LAND OF A SINGLE TREE. I? 



until at last they meet, and each grasping the other's claws, 

 raises them aloft, and then for five minutes they circle about 

 in most ludicrous imitation of a waltz. All this usually takes 

 place on the lower surface of a mangrove trunk, the inverted 

 position apparently making no less secure the footing of the 

 little dancers. We could not decide whether this perform- 

 ance was in the nature of courtship or just pure play. 



What we did discover concerning the lives of these crabs 

 was full of interest. Hundreds of the smallest-sized ones 

 lived in holes in the mud, and when the tide went down they 

 came out and ran about intent on some all-important busi- 

 ness of their little existence. Another class of larger individ- 

 uals had their holes near the roots of the mangroves, one 

 (rarely two) good-sized crab apparently taking possession of 

 each root. Here he disported himself, running up and down, 

 from the water into the air with no change in speed, and here, 

 strangest of all, he grew to resemble his home root. There 

 was as great diversity among the roots as among the larger 

 trunks whitish, black, mottled, and all intervening shades. 

 It was a fact, of which we had hundreds of daily proofs, that 

 the crabs were so like their particular root that often we could 

 not detect the quiescent crustacean when within a foot of our 

 faces. 



There was one group of five black roots forming a rough 

 circle about a single mottled root. As we approached, a 

 crab ran down each stalk into the water, and as we peered 

 down and saw them go into their holes, we could at a glance 

 tell the mottled crab from the five black ones. Even the roots 

 which were as yet a foot or more above the bottom mud 

 each had their occupant, which thus had to swim upward 

 from his hole before he could grasp his swaying perch. 



A third class of crabs lived among the higher trunks and 

 branches of the mangroves, and, except where there was 

 a highroad of some large trunk dipping into the water, these 



