1836.] GREAT CRAB. 463 



for a crab to open a strong cocoa-nut covered with the husk ' 

 but Mr. Liesk assures me that he has repeatedly seen this 

 effected. The crab begins by tearing the husk, fibre by fibre, 

 and always from that end under which the three eye-holes are 

 situated ; when this is completed, the crab commences hammer- 

 ing with its heavy claws on one of the eye-holes till an opening 

 is made. Then turning round its body, by the aid of its pos- 

 terior and narrow pair of pincers, it extracts the white albu- 

 minous substance. I think this is as curious a case of instinct 

 as ever I heard of, and likewise of adaptation in structure be- 

 tween two objects apparently so remote from each other in the 

 scheme of nature, as a crab and a cocoa-nut tree. The Birgos 

 is diurnal in its habits ; but every night it is said to pay a visit 

 to the sea, no doubt for the purpose of moistening its branchiae. 

 The young are likewise hatched, and live for some time, on the 

 coast. These crabs inhabit deep burrows, which they hollow 

 out beneath the roots of trees ; and where they accumulate sur- 

 prising quantities of the picked fibres of the cocoa-nut husk, on 

 which they rest as on a bed. The Malays sometimes take ad- 

 vantage of this, and collect the fibrous mass to use as junk. 

 These crabs are very good to eat; moreover, under the tail of the 

 larger ones there is a great mass of fat, which, when melted, some- 

 times yields as much as a quart bottle full of limpid oil. It has 

 been stated by some authors that the Birgos crawls up the 

 cocoa-nut trees for the purpose of stealing the nuts : I very 

 much doubt the possibility of this ; but with the Pandanus* the 

 task would be very much easier. I was told by Mr. Liesk that 

 on these islands the Birgos lives only on the nuts which have 

 fallen to the ground. 



Captain Moresby informs me that this crab inhabits the 

 Chagos and Seychellc groups, but not the neighbouring Maldiva 

 archipelago. It formerly abounded at Mauritius, but only a 

 few small ones are now found there. In the Pacific, this species, 

 or one with closely allied habits, is saidf to inhabit a single 

 coral island, north of the Society group. To show the wonder- 

 ful strength of the front pair of pincers, I may mention, that 

 aptain Moresby confined one in a strong tin-box, which had 





* See Proceedings of Zoological Society, 1832, p. 17 

 "f Tyemian and Bennett. Voyage, &c., vol. ii., p. 33. 



