The rock on Pig Island, where exposed at some of the points, is mica slate, soft and splintery in many places, with frequent veins of quartz.

The hills,* although often running in ridges, have a rounded outline, and the soil on the smooth grassy places--comprising three-fourths of the island--is composed of disintegrated rock mixed with pieces of undecomposed quartz, any considerable accumulation of vegetable mould being probably prevented by the heavy rains.

The grass is very luxuriant without being rank; it was not known to me, for, unlike most of the other plants, I had not met with it in Australia.

Indeed the frequency of the coconut-palm was the only non-Malayo-Australian feature in the vegetation.

As no botanist had previously visited the Louisiade, a few of the principal plants may be mentioned.