[135]

As a proof of more rapid growth externally than internally.─ 

It must be remembered that much of the sand in lagoon, & all dry land is the growth of outside as well as foundation on the strips.— (Mem: same argument at Tahiti)(& all detritus on profound external slope) If the fact that those strong species which alone could withstand pressure pr require (which is analogy to limited powers of accommodation of the lower orders) require pure breaking water the whole difficulty of shor barrier of shoal coral is done away with ─ muddy flat [sketch]

'As a proof of more rapid growth externally than internally.─', '& all detritus on profound external slope', 'Mem: same argument at Tahiti'] ink insertions, otherwise document begun in pencil.

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I rely much on nature of foundation in lagoons [appear] rocky

(NB. the shallower the lagoon the more fresh water would be injurious.— (add this [sketch?]

Islets (& in proportion to size of lagoon). when there is a foundation there are reefs.— V. Gambier. Mannicollo. Barrier reefs, latter strongest example.— It might be made foundation of argument: Where in a lagoon do we see much reefs: rocky shores.— answer.—

NB. When we anchored the most impassable white mud.—

'(add this [sketch?]', 'NB. When we anchored the most impassable white mud.—'] in pencil.

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At Tahiti within lagoon: when shore was of coral, coral lined, where sand nothing: [sketch?]

Mem: introduce [sketch?] to K Georges Sound that calc beaches are found.— [sketch?]

[sketch?] Mem: introduce [sketch?] to K Georges Sound that calc beaches are found.—] in pencil.

[135v]

Looking at the nature scale of a Lagoon Island, some cause must retard the growth the coral in the lagoon as compared to the outer.— I exclude here the conversion into dry land by cemented fragments─ In the first places, the most solid kind Astræa Madrepora & Corallina appear only flourish outside,— The weak branched kinds must be inefficient as compared to the more solid ones.—

The absolute height outside must be more than within (which however chiefly affects the formation of dry land) — The sand thrown through the opening of the reefs — (& not removed when once there: the calc mud must be fatal) — the Fresh water.— the fish & perhaps other animals.— When near land sediment from coast, sandy or muddy beaches, disturbance by swell.— The branching corals are known to increase very rapidly, but I have expatiated on the difficulty of absolutely filling up the last 5 ft (or rather more) water:— Where much is dead, the water may be turbid & injurious to the growth of corals [sketch] I rely most on greater absolute heights & strong kinds & slippery bottom of sand or mud

Page in pencil. 'which however chiefly affects the formation of dry land', '& not removed when once there: the calc mud must be fatal', '(or rather more)', '& slippery bottom of sand or mud'] ink insertions.