I have before alluded to a crab which lives on the cocoa-nuts; it is
very common on all parts of the dry land, and grows to a monstrous
size: it is closely allied or identical with the Birgos latro. The
front pair of legs terminate in very strong and heavy pincers, and the
last pair are fitted with others weaker and much narrower. It would at
first be thought quite impossible 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 hammering 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 posterior and narrow pair of
pincers, it extracts the white albuminous substance. I think this is as
curious a case of instinct as ever I heard of, and likewise of
adaptation in structure between 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 surprising quantities of the
picked fibres of the cocoa-nut husk, on which they rest as on a bed.
The Malays sometimes take advantage 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 mass of fat, which, when melted,
sometimes 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 [8] 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
Seychelle 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 said [9] to inhabit a single coral island, north of the
Society group. To show the wonderful strength of the front pair of
pincers, I may mention, that Captain Moresby confined one in a strong
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