174 
THE OCEAN WORLD. 
system of obscure circulation, and the ova are produced in an organ 
distinct from the separate individuals. For,” adds Mr. Darwin, in a 
note, “the cavities leading from the fleshy compartments of the 
extremity were filled with a yellow pulpy matter which, under a 
microscope, consisted of rounded semi-transparent grains aggregated 
together into particles of various sizes. All such particles, as well as 
separate grains, possessed the power of rapid motion, generally revolving 
round different axes, but sometimes progressive.” 
The description of the Island of Cocos or Keeling is as follows : — 
“ The ring-formed reef of the lagoon island is surmounted, in the 
greater part of its length, by linear islets. On the northern, or 
leeward side, there is an opening through which vessels can pass to 
the anchorage within. On entering, the scene was very curious, and 
rather pretty ; its beauty, however, entirely depended on the brilliancy 
of the surrounding colours. The shallow, clear, and still water of 
the lagoon, resting in its greater part on white sand, is, when illu- 
mined by a vertical sun, of the most vivid green. This brilliant 
expanse, several miles in width, is on all sides divided, either by a line 
of snow-white breakers from the dark heaving waters of the ocean, or 
from the blue vault of heaven by the strips of land crowned by the 
level tops of the cocoa-nut tree. As a white cloud here and there 
affords a pleasing contrast to the azure sky, so in the lagoon bauds 
of living coral darken the emerald-green water. 
“ The next morning I went ashore on Direction Island. The strip 
of dry land is only a few hundred yards in width ; on the lagoon side 
there was a white calcareous beach, the radiation from which, under 
this sultry climate, was very oppressive. On the outer coast, a solid 
broad flat of coral rock served to break the violence of the open sea. 
Excepting near the lagoon, whero there is some sand, the land is 
entirely composed of rounded fragments of coral. In such a loose, 
dry, stony soil, the climate of the intertropical regions alone could 
produce so vigorous a vegetation. On some of the smaller islets, nothing 
could be more elegant than the manner in which the young and full- 
grown cocoa-nut trees, without destroying each other’s symmetry, 
were mingled into one wood. A beach of glittering white sand formed 
a border to those fairy spots. 
“ The natural history of these islands, from its very paucity, possesses 
peculiar interest. The cocoa-nut tree, at the first glance, seems t o 
