40 Dr Chanilsso on the Co7'al Islands of the Pacific Ocean: 
but this, and the extent of each, probably depends on the size 
of the sub-marine mountain tops, on which their basis is found- 
ed. Those islands which have more length than breadth, and 
are opposed in their greatest extent to the wind and waves, are 
richer in fruitful islets than those whose situation is not so adapt- 
ed to a quick formation. In the large island-chains, there are 
always some single islets which have the appearance of high 
land : these lie upon ah angle projecting into the sea, are ex- 
posed to the surf from two sides, consist therefore almost en- 
tirely of large blocks of coral, and are destitute of smaller frag- 
ments of shells and coral sand to fill up the intervals. They , 
are, therefore, nht adapted to support plants requiring a depth 
of soil, and only afford a basis to high trees, provided with 
fibrous foots, (as the Pisonia^ Cordia Sebastiana, L. ; Morm- 
da citrifolia^ L., and Pandanus odoratissimus, L.) which, at a 
distance, give to these, always very small, islands the form of a 
hill. The inner shores of the island, exposed to the surf, con- 
sist of fine sand, which is washed up by the tide. Between the 
small islands under their protection, and even in the middle of 
the inner seaj are found smaller species of coral, which seek a 
quiet abode, forni in time, though very slowly, banks, till they 
at last reach the surface of the water ; gradually increase in ex- 
tent, unite with the islands that surround them, and at length 
fill up the inner seas, so that what was at first a ring of islands, 
becomes one connected land. The islands which are so far 
formed, retain in the middle a fiat place, which is always lower 
than the wall that surrounds them on the banks ; for which 
reason pools of water are formed in them after a continued 
rain,- — -the only springs and wells they possess. One of the 
peculiarities of these islands is, that no dew falls in the evening, 
that they cause no tempests, and do not check the course of the 
wind. The very low situation of the country sometimes ex- 
poses the inhabitants to great danger, and threatens their livesj 
when the waves roll over their islands, if it happens that the 
equinox and full moon fall on the same day, (consequently, 
when the water has reached its greatest height,) and a storm 
agitates the sea at the same time. These islands are said to be 
also shaken by earthquakes. 
