236 
FOXWORTHY. 
The rate of growth is not known^ but it is believed to l)e fairly rapid 
for some species. 
So far as known, there are no Loranthaceous parasites on Philippine 
dipterocarps. The trees are usually comparatively free from climbing 
vines. 
Old trees are frequently badly affected with a heart rot and are hollow 
at the center. In red lauan^ (Shorea negrosensis) in N"egros, there is 
a peculiar kind of heart rot which destroys a considerable amount of 
lumber and which is known as soft heart. The wood for some distance 
about "the center of the log is very brash and will break with its own 
weight. It is not noticeably different in color from the rest of the heart- 
wood. This seems to be caused by a species o£ 'fungus {Pyropolyporm) . 
This soft heart is apparently succeeded by the hollow heart in the older 
trees. 
Standing, healthy trees do not seem often to be attacked by insects, 
but fallen or diseased trees have a great many insect enemies. Seasoned 
wood of some species is badly attacked by beetles, the "pin-hole" and 
"shot-hole" borers. 
Some forms of leaf- and stem-galls are common on certain species. 
Certain large galls are often mistaken for fruit in Sliorea guiso, 8. teys- 
manniana, and some other species. 
DISTRIBUTION. 
Fossil remains. We have an example of a piece of wood belonging to 
this family which was collected from a ledge in Cavite Province. 
Brandis, in his "Enumeration/' credited twenty-iive species to the Phil- 
ippines, five of these being considered extra- Philippine in distribution. 
We now recognize almost double the number of species in the Islands and 
about one-third of all our species are known to be extra- Philippine, while 
quite a number of others are so closely related to extra-Philippine species 
or are so little understood that it is altogether probable that we will find 
most of our species to be extra-Pliilippine when we come to understand 
them better. 
It is apparent that our dipt^rocaips are most closely related to those 
of Borneo and the Malay Peninsula. This near relationship is much 
more significant than the mere number of species would indicate, because 
the species are so rich in individuals and constitute such an important 
part of the forest where they occur. 
The extreme northeastern distribution of the family is found in the 
Philippines. 
The following table is to show the distribution of the Philippine species 
80 far as it is known : 
