The next day the boat’s head was turned homewards.  And what had been learnt at the little bay of Alice Biscayen suggested, as we went on, a fresh geological question.  How the outer islands of the Bocas had been formed, or were being formed, was clear enough.  But what about the inner islands?  Gaspar Grande, and Diego, and the Five Islands, and the peninsula—­or island—­of Punta Grande?  How were these isolated lumps of limestone hewn out into high points, with steep cliffs, not to the windward, but to the leeward?  What made the steep cliff at the south end of Punta Grande, on which a mangrove swamp now abuts?  No trade-surf, no current capable of doing that work, has disturbed the dull waters of the ’Golfo Triste,’ as the Spaniards named the Gulf of Paria, since the land was of anything like its present shape.  And gradually we began to dream of a time when the Bocas did not exist; when the Spanish Main was joined to the northern mountains of the island by dry land, now submerged or eaten away by the trade-surf; when the northern currents of the Orinoco, instead of escaping through the Bocas as now, were turned eastward, past these very islands, and along the foot of the northern mountains, over what is now the great lowland of Trinidad, depositing those rich semi alluvial strata which have been since upheaved, and sawing down along the southern slope of the mountains those vast beds of shingle and quartz boulders which now form as it were a gigantic ancient sea-beach right across the island.  A dream it may be:  but one which seemed reasonable enough to more than one in the boat, and which subsequent observations tended to verify.

CHAPTER VII:  THE HIGH WOODS

I have seen them at last.  I have been at last in the High Woods, as the primeval forest is called here; and they are not less, but more, wonderful than I had imagined them.  But they must wait awhile; for in reaching them, though they were only ten miles off, I passed through scenes so various, and so characteristic of the Tropics, that I cannot do better than sketch them one by one.

I drove out in the darkness of the dawn, under the bamboos, and Bauhinias, and palms which shade the road between the Botanic Gardens and the savannah, toward Port of Spain.  The frogs and cicalas had nearly finished their nightly music.  The fireflies had been in bed since midnight.  The air was heavy with the fragrance of the Bauhinias, and after I passed the great Australian Blue-gum which overhangs the road, and the Wallaba-tree, {120a} with its thin curved pods dangling from innumerable bootlaces six feet long, almost too heavy with the fragrance of the ‘white Ixora.’ {120b} A flush of rose was rising above the eastern mountains, and it was just light enough to see overhead the great flowers of the ’Bois chataigne,’ {120c} among its horse-chestnut-like leaves; red flowers