IN THE COCOS'KEELTNG ISLANDS. 25 



Among the branches of the ginger-coral, a great variety of 

 Crustacea are to be seen cree^Ding about, and in all the crevices 

 Mollusea of every family, most cons|)icuous among them being 

 the giant clams of the genus Trldacna, whose mantle edged with 

 turquoise beads forms a beautiful object to look down on ; but 

 one must shudder for the diver who should accidentally thrust 

 his head or a limb into its gape, which the slightest touch 

 causes to close with a snap. 



Nor Avas the interest of the atoll confined to its surf-beaten 

 barrier and its teeming lagoon ; eYery foot of the surface of the 

 land, every atom of its substance, every stem of the vegetation 

 that covered it, and each separate existence that crept or 

 winged itself on and around it, by its very presence in this 

 mid-ocean speck, was charged with a Avondrous tale of strange 

 vicissitudes and wanderings. By the inner margins of some 

 of the islands (as will be seen on looking at' the map), and 

 forming higoonlets in some of them, there are soft limy mud- 



O ^"O 



flats, which are gradually becoming land, mainly by slow 



elevation and by crustacean agency. 



One of the largest of these is in ^Ycst Island. Its lagoon- 

 ward portion, near the entrance conduit, which is submerged 

 at high water, is tenanted by two, if not three, species of 

 crab {Gelasimus vocans, tetyago7io7i, and anmilijpes). They live 

 in narrow corkscrew burrows, round the top of which there 

 is always a little mound just such as is seen about an earth- 

 worm's; and indeed they are most perfect worm substitutes. 

 I counted one hundred and twenty of their holes in an area 

 only two feet square ; and as there were many square acres in 

 the ground of which I speak, some idea of the number of this 

 busv army may be obtained. They were incessantly active 

 during the recess of the tide and even during high water 

 which is generally perfectly still, in carrying down twigs of 

 trees or fucus leaves, scraps of cocoanut shell, and seeds, 

 laying the foundation of the future land. 



On placing the foot on the region occupied by them, one 

 perceives an undulation of the surface followed, over a circular 

 area, bv a surprising change of the pure white ground mto a 

 warm pink colour, which for the moment the stranger puts down 

 to some affection of his eyes from the reflection of tlie light. 

 He soon perceives that this movement is caused by the simul- 



