BY ir. B. GUPPY, M.B. G63 



late Mr. Darwin, in his Journal of the Beagle (p. 468, edit 1860), 

 thus describes the manner in which these crabs remove the husk 

 and perforate the hard shell, on Keeling Island, as observed by- 

 Mr. Liesk, an English resident. '' After the husk has been 

 removed fibre by fibre, the crab commences to hammer an opening 

 in one of the eye-holes until an opening is made. It then turns 

 round its body and extracts the white meat inside." From this 

 description it would seem that a circular opening would be formed, 

 •whilst in the particular instance of this cocoanut the angular 

 form of the opening, together with the appearance of the edge?, 

 ■would incline me to the opinion that the hole had been formed 

 partly by biting and partly by the rasp-like surface of the big 

 pair of claws. It is worthy of note that I observed no fragment 

 of the shell in the milk within the nut. 



I kept the JBirgus alive on board on a diet of coconuts for three 

 weeks, when one morning, to my great disappointment, I found 

 it dead. Other foods, such as bananas, were offered to it, but 

 were left untouched. Its appetite for cocoa nuts continued un- 

 impaired to the last day of its life. Mr. Isabel, • leading stoker 

 of this ship, who looked after it very attentively, tells me that 

 its average rate of consumption was about two cocoanuts in three 

 days. A number of these crabs in a cocoanut plantation might 

 therefore prove a considerable pest ; and if this represents the 

 quantity of food which the Birgus consumes in a state of nature, 

 a single crab in the course of twelve months would dispose of 

 about 250 cocoanuts, which represents the annual production of 

 two to three palms, and between twenty and thirty quarts of 

 cocoanut oil. Being desirous of observing the manner in which 

 the husk was removed, I had a cocoanut with its husk on placed 

 in the coop in which the crab was kept. On one occasion the 

 Birgus was surprised with the nut between its large claws ; but 

 notwithstanding that no other food was offered to it for a day 

 and a half it did not attempt to strip oft' the husk. So the opera- 

 tion was done for it, and a small hole was knocked in the top of 



