200 '^he Philippine Journal of Science isn 
an area as the grass, and on the north slope of Mount Pirapiraso 
the trees cover more than 50 per cent of the ground. A com- 
parison with Gates’s pictures indicates that trees are now more 
numerous in this region than in 1914. Their greatest develop- 
ment is in the ravines. Scattered clumps of bamboos also occur 
in this locality. The latter are apparently the same ones that 
were seen by Gates. In this region the second-growth forest 
is better developed than on any other part of the island, and 
here we find the most complex vegetation. Many species are 
found in the immediate vicinity of Pirapiraso that were not 
observed elsewhere on the island. The thickets are so dense in 
many of the ravines and on some of the northern slopes, that 
it is difficult to penetrate them, the bushes and small trees being 
often overgrown by a tangled mass of herbaceous and woody 
vines. 
On the divide between the former towns of Pirapiraso and 
Bignay Gates found a stand of Imperata cylindHca and Sac- 
charum spontaneum. Scattered trees were also present. Sac- 
charum has apparently invaded much of the area occupied by 
Imperata, a much smaller grass, and is at present much more 
prominent than the latter. 
Mount Ragatan runs diagonally across the base of the north- 
eastern peninsula. Gates found this rather densely covered with 
grass, shrubs, and small trees. The grass on the northern slope 
is now fairly dense. Trees are numerous in the ravines, but 
scarce on the ridges. On the eastern and western slopes the grass 
is well developed, but numerous bare strips running with the 
slope make it fairly easy to penetrate. On the southern slope 
the vegetation is largely Saccharum, which is still open enough 
to allow one to pass through it readily. 
Southwest of Mount Ragatan is a crescent-shaped ridge, Mata- 
as-na-golod. In October, 1913, the vegetation on this mountain 
consisted almost entirely of Saccharum in clumps and extended 
about two-thirds of the way to the top. By December it had 
reached the top. The vegetation in 1917 still consists almost 
entirely of Saccharum, which has not yet formed a stand of its 
normal density ; although on the northern slopes the bare ground 
occurs only as numerous patches, which usually appear much 
smaller than a clump of Saccharum. On many of the ridges on 
the southern slopes there are considerable areas that are almost 
bare. This mountain is the promnnent peak in Plate XII, fig. 1. 
It is not clear what Gates meant when he said that a closed stand 
of Saccharum occurred on the western, eastern, and northern 
