The forest here was composed for the most part of trees which had already been met with near the lake and on Prospect Heights. There were deodars, Douglas firs, casuarinas, gum trees, eucalypti, hibiscus, cedars, and other trees, generally of a moderate size, for their number prevented their growth.

Since their departure, the settlers had descended the slopes which constituted the mountain system of the island, on to a dry soil, but the luxuriant vegetation of which indicated it to be watered either by some subterranean marsh or by some stream. However, Cyrus Harding did not remember having seen, at the time of his excursion to the crater, any other watercourses but the Red Creek and the Mercy.

During the first part of their excursion, they saw numerous troops of monkeys who exhibited great astonishment at the sight of men, whose appearance was so new to them. Gideon Spilett jokingly asked whether these active and merry quadrupeds did not consider him and his companions as degenerate brothers.