me, 4 Brown, Merrill and Yates: Volcano Island 243 
The eruption of 1911 completely destroyed the vegetation over 
most parts of* the island, while in the extreme northern part a 
few bamboos, bananas, trees, and possibly some grass escaped. 
In the revegetation of the island a single species of grass, 
Saccharum spontaneum, is so much the most prominent of all 
the invaders that it gives character to the whole vegetation. 
Except in the northern part of the island, it occurs as scattered 
clumps. Besides Saccharum the other most conspicuous elements 
are scattered trees. 
The revegetation is proceeding slowly owing, probably, to 
adverse environmental conditions, the mos't prominent of which 
are the presence of excessive amounts of sulphates in the soil; 
the lack of weathering of the soil particles; the scarcity or 
absence of humus; the scarcity of nitrogen; the low water- 
holding capacity of the soil ; and erosion. 
Two hundred ninety-two species of plants have been found 
on Volcano Island since the eruption. These represent 232 
genera and 66 families. 
Most of the species of plants on Volcano Island are those of 
wide geographic distribution. Ninety-six, or 36 per cent, are 
found in the tropics of both hemispheres, while an additional 
one hundred fifty, or 51 per cent, are found in other parts of 
the Indo-Malayan regions as well as in the Philippines. 
Very few of the species of plants on Volcano Island have 
found favorable habitats over any considerable area, as only 13 
are common and widely distributed. 
Birds seem to have been the most important agency in bring- 
ing different species to Volcano Island, as 54 per cent of the 
total on the island could have been carried to it by this means. 
