VITI ISLANDS. 341 
cut up into numerous islands by the intersecting mouths. It consists 
of fine mud from the basaltic rocks of the mountains, and near Rewa, 
which is six miles from its mouth, scarcely a pebble as large as a 
walnut is to be seen. The bed of the river often changes its position ; 
and during freshets, large portions of the banks are carried off, which 
form shifting sand-banks in the body of the stream, or are transported 
to the bay, where several large shoals have been accumulated. I 
learned from a foreigner who had resided there the preceding ten years, 
that the river at Rewa had doubled its breadth in that time; and the 
numerous cocoanut stumps which stood far out in the stream, attested 
this fact. Another person, who had resided there forty years, stated 
that during this period, the deposits had lengthened the river half a 
mile, by encroaching this much on the bay; but I know not how 
much reliance should be placed on this evidence. All attempts to 
arrive at more satisfactory results as to the rate of progress in the ex- 
tension of the delta, proved unavailing. The surveys of the river 
and harbour by the Expedition will afford data for future comparison 
to those who may follow us. 
The water from this river has destroyed all the living coral on the 
inner margin of the barrier reef, which, where nearest, is about two 
and a half miles from its mouth ; and, moreover, the whole surface of 
the reef scarcely bears a live branch, except towards its outer limits, 
and there, the species are but few and small. ‘There was a time when 
growing coral was forming these reefs which are now lifeless, and the 
period was sufficiently long to widen the barrier reef to one or two 
miles. We have no reason to suppose less rain to have fallen then 
than now; and how was it carried off without injury to the growing 
reefs? for the various mouths are all fronted by reefs, and none are 
more than five miles distant. We may, perhaps, refer to the period, 
when, before the formation of the delta, the river’s mouth was several 
miles nearer the mountains than at present. But still this distance of 
the reef from the river may not have been necessary ; for the water 
of the island streams freshens the surface only to the depth of the 
river itself, and can destroy growing coral to no greater depth. 
Other rivers, of equal size, exist on the island of Viti Lebu, but 
this is the only one examined. 
Vanua Lebu, the second island among the Feejees, has a much less 
uneven surface than Viti Lebu. Few of the summits exceed two 
thousand feet in elevation, and none are more than three thousand 
feet. ‘The ridges are lower on the west side, and less irregular, with 
86 
