140 A NATUBALI8T IN CELEBES ch. vi 



the genus Calappa, and when at rest it has a remarkable 

 resemblance to a lump of old water-worn coral stone. This 

 protective resemblance is brought about by the chelae being 

 large and rugged, and fitting tightly to the carapace, which 

 is also very uneven in appearance. On many occasions, 

 when I saw these little fellows lying half-buried in the sand 

 I was at a loss to know whether they were really crabs or 

 only stones, until I turned them over with a stick. 



I must now pass on to the fourth section of this chap- 

 ter — the Mangrove Swamps. When the naturalist first 

 enters the mangrove swamp he cannot fail to be impressed 

 with two things : the enormous field' for investigation in 

 animal and vegetable life that it affords, and the extreme 

 difficulty and discomfort of doing any work there. The 

 various kinds of mangrove trees bearing creepers, orchids, 

 and parasitic ferns, the swarms of ants, termites, flies, 

 mosquitoes, and other creatures of the air ; the snakes, 

 birds, fishes, crabs, anemones, and worms afford endless 

 themes for investigation and research. On the other hand, 

 the damp, stifling, malarious atmosphere and the insect 

 pests are quite sufficient to drive away even the enthusiastic 

 naturalist to purer air and more wholesome places. 



In localities where the swamp is tolerably broad, the 

 trees on the shoreward side are very lofty, but they 

 gradually become shorter as they approach the seaward 

 limit, where they are in many cases not more than ten or 

 fifteen feet in height. The swampy ground is covered with 

 a network of root-branches averaging about a couple of 

 inches in diameter, and in the intervals between them there 

 is a black slimy mud, with patches here and there of hard 

 dry sand, and several shallow pools and puddles. It is not 

 an easy place to walk about in, for one has to be extremely 

 careful when treading on the slimy roots not to slip over, 

 and not to leave a boot behind in the soft sticky mud 



