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PACIFIC SCIENCE, Vol. VII, April, 1953 
two small islands (Kano, 1931). However, it 
has been shown that the southern tip of For- 
mosa, commonly known as the Hunchuen 
(Koshun) Peninsula, has a flora quite dis- 
tinct from that of the Formosan mainland but 
very close to that of these two small islands, 
showing similarly distinctive relationships 
with the Philippine flora. There is a marked 
infiltration of austral elements from the Phi- 
lippines to Formosa, particularly in the ex- 
treme southern part of the island and in these 
two small islands (Li and Keng, 1950). 
SOUTHWARD MOVEMENT OF 
TEMPERATE ELEMENTS 
Before the inception of this northward mi- 
gration of relatively recent occurrence, as will 
be discussed later, there occurred another ex- 
pansion of floristic elements in the opposite 
direction, that is, from Formosa to the Phi- 
lippines. These elements, in contrast to the 
southern tropical elements, mostly of the low- 
lands, are cold-temperate in nature and lim- 
ited to montane or alpine regions. In Formosa, 
because of the massive and lofty mountain 
ranges which occupy most of the central por- 
tion of the island, there developed an exten- 
sive alpine-montane flora rich in number of 
species. These plants show distinctively close 
relationships with those of western China and 
the eastern Himalayas and also to some ex- 
tent with the montane flora of Japan in the 
north. 
There are over 40 peaks in the Formosan 
mountain systems that exceed 1,000 meters 
in height. The highest peak is Yu Shan, or 
Mt. Morrison, towering to a height of 1,950 
meters, the highest of all eastern Asia. Such 
an extensive, high mountain chain permits the 
existence of an alpine flora that otherwise 
exists only in the Himalayas, western China, 
and other mountain regions far north of For- 
mosa. 
From Formosa, a large number of tem- 
perate elements, mostly of mountain regions, 
extend southward to the Philippines. In the 
Philippine Islands, these Asiatic elements are 
largely confined to medium and high altitudes 
in northern Luzon. Such characteristically 
northern or Asiatic elements, mostly common 
genera in the mountains of Formosa, such as 
Ltlium^ Liriope, Saururus, Tbesmm, Arenaria, 
Sedum, Duetzia, Rosa, Skimmia, Buxus, Pistacia, 
Androsace, Hoppea, Salvia, Ellisiophyllum^ Hemi- 
phragma, Peracarpa, Aster, Solidago, Anisopap- 
pus, and Artemisia, occur nowhere in the Ma- 
layan region outside of northern Luzon (Mer- 
rill, 1923 - 26 ). It is apparent that Formosa is 
an important route of migration of these 
Asiatic types to the regions in the south (Van 
Steenis, 1946). 
We may picture that during the Pleistocene 
or earlier, when the general temperature was 
much lower than now, these montane species 
would have inhabited lower elevations and 
thus had greater ranges. Their ranges might 
have been more or less continuous, extending 
from the Himalayas and western China through 
the mountains of southern China to Formosa 
and Luzon. Subsequent rising of tempera- 
tures forced these plants to higher elevations 
until finally they occupied the present iso- 
lated mountain regions suitable for their exist- 
ence. Thus, species like Hemiphragma hetero- 
phyllum Wall, and Ellisiophyllum pinnatum 
(Wall.) Makino now have widely disjunct 
ranges on the high mountains of Luzon, For- 
mosa, western China, and the eastern Hima- 
layas, etc. 
These Philippine plants of northern origins 
are sometimes specifically or subspecifically 
distinct from their congeners in Formosa, 
while others may be specifically identical. 
That some of these show morphological dif- 
ferentiation indicates that their separation 
must have been for a considerable length of 
time. As such plants are now confined to 
isolated and distant mountain regions and as 
there were drastic changes in climate during 
the geologically recent past, such a south- 
ward migration of the montane flora may be 
considered largely a matter of the past, there 
being little possibility that the same process 
is going on extensively at the present. 
