182 
VOYAGE TO THE 
CHAP, cession of ledges being brought to the surface, while, by the same pro- 
cess, the lagoon will gradually become more shallow and contracted. 
Feb. The ridges are particularly favourable to the formation of a soil, 
by retaining within them whatever may be there deposited until it 
decays, and by protecting the tender shrubs during their early growth. 
Near our observatory the soil had attained a depth of about eight inches 
before we came to broken coral. 
“ In the central and sheltered parts of the plain between the ridges 
the pandanus spreads its divergent roots and rears its fruitful branches ; 
the pemphis also takes root in the same situation. The loose dry 
stones of the first ridge are penetrated by the hard roots of the tefano, 
which expands its branches into a tall spreading tree, and is attended by 
the fragrant suriana, and the sweet-scented tournefortia, in the shelter of 
whose foliage the tender achyranthus and lepidium seem to thrive the 
best. Beyond the first high and stony ridge the hardy scmvola extends 
its creeping roots and procumbent verdure towards the sea, throwing 
its succulent leaves round the sharp coral stones.” 
“ On the windward side, wherever the pandanus was devoid of the 
protection of the more hardy trees, the brown and decayed leaves 
showed it had advanced beyond its proper boundary^.” 
We quitted Bow Island on the 20th of February, and continued 
the survey of the archipelago, until the period had arrived when it 
was necessary to proceed direct to Otaheite, to prepare the ship for her 
voyage to the northward. We were greatly retarded toward the close 
of our operations by the rainy season, which was attended with calms, 
and hot, sultry, wet weather, and perhaps, had we continued at sea, 
would have prevented any thing more being done. The dysentery about 
this time began to make its appearance among the ship’s company, 
owing no doubt to the rains and closeness of the atmosphere, com- 
bined with the harassing duty arising from the navigation of a sea so 
thickly strewed with islands, and to the men having been a long time 
on a reduced allowance of salt provisions. 
The islands which were visited between Bow Island and Otaheite 
* Mr. Collie’s Journal. 
