162 ! The Philippine Journal of Science 1916 
but on the broad slopes and in narrow ravines at intermediate 
points. Depending on the prevailing winds, exposure, rainfall, 
etc., the flora of one side of a mountain may be decidedly distinct 
from that of the opposite side, in some cases very radically 
different. Manifestly then, no single mountain in the Philip- 
pines can be considered botanically thoroughly explored, al- 
though some of them, such as Banajao, Mariveles, Santo Tomas, 
and Maquiling, have been ascended by very numerous collectors 
and botanists; in most cases only single slopes have been ex- 
plored. 
No complete summary of the Philippine flora has been pub- 
lished that is at all reliable. F.-Villar and Naves* admitted 
4,479 species of flowering plants and ferns, but nearly 2,000 
of the admitted species do not occur in the Philippines. Up 
to the close of the last century but a few more than 2,500 
species were definitely known from the Philippines. A rather 
careful estimate made by me in the early part of the year 1909, 
considering only those forms that had been determined to the 
species, gave a total of 5,678. The great amount of work that 
has been accomplished during the past few years has vastly 
increased this list of known species, and my present estimate 
is somewhat over 7,000. It is confidently expected that when 
the Philippine flora is merely fairly well known the total 
number of species, excluding the cellular cryptogams, will be 
found to exceed 10,000. It is clear, also, that most of the future 
additions to our knowledge of the flora will be in the nature 
of new species, rather than in the discovery in the Archipelago 
of species already described from extra-Philippine specimens. 
Our present knowledge of the Philippine flora is to a large 
degree based on the botanical collections assembled by the Bu- 
reau of Science. This herbarium now exceeds 150,000 mounted 
specimens, of which over 90,000 are Philippine. Accessions 
have been so numerous at times that it has been impossible, 
with our limited force, properly to study all the material re- 
ceived, and the result is that very many manifestly undescribed 
forms are represented in the collections by from one to several 
specimens that must be considered at a later date when there 
is opportunity to study the material or to revise various groups. 
The collections comprise not only the flowering plants and ferns, 
but also a very extensive series of fungi, mosses, scale mosses, 
and lichens. In exchanges a most liberal policy was adopted, 
and in the past thirteen years more than 240,000 duplicates 
* Novis. App. Fl. Filip. 4* (1880-83) 1-375. 
