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DR. O. STAPF ON THE FLORA OF MOUNT KINABALU 117 
it. Then the shore-line shifted again the other way. The Bornean islands were joined 
into one. The floras of these islands, advancing with the advancing coast, met, and a 
fresh exchange took place, which, however, could not materially affect the highland 
floras, for they were still separated by the lowland. ‘The exchange and the ensuing 
generalization of the flora remained therefore confined to the lower zones, whilst the 
highlands maintained their individual character. In still more recent time man became 
an agent in dispersion and in generalizing the character of the flora. Large parts of the 
“old jungle " fell by knife and fire, and although the original vegetation generally springs 
up again and again with apparently unabated vigour, there can be no doubt that many 
of its feebler elements have already succumbed in this struggle. Others better adapted 
to the new conditions took their place, and, often favoured by particular means and con- 
ditions of dispersion, spread far and wide. A “secondary ” vegetation thus replaced the 
primary or aborginal one, a change in which the hill-zone flora of Kinabalu shared 
equally with the flora of any part of the lowlands or the hills where man settled. 
The last point with which I wish to deal concerns the bearing of the results of the 
examination of the flora of Kinabalu on the general differentiation of the Indo-Malayan 
flora. The flora cf Kinabalu is a new proof of the essential unity of the Indo-Malayan 
flora west and east of Kinabalu or the Macassar line. But the flora of the Austro- 
Malayan division differs at leastas much from that of the Malayan division as the latter 
differs from the flora of the Himalaya region or of Indo-China, True, the relationship of 
the Malayan and Austro-Malayan floras is very much closer if we take into consideration 
the floras of the coasts, lowlands, and hills, and they become almost uniform if we confine 
the comparison to the shore vegetation. Yet this is the least stable portion of the flora, 
and therefore teaches us almost as little about the history and the affinities of the flora 
as a comparison of weeds would do. We have therefore to rely on the most conservative 
portion of the flora, the flora of the primary forest, and particularly of the highland 
forest. I drew the line between Malaya and Austro-Malaya in accordance with Wallace’s 
Macassar line, chiefly because it almost coincides with the meridian of Kinabalu. If I 
had included Celebes in Malaya, very few species would have been added to the list of 
the Malayan elements of the primary flora. It must, however, not be forgotten that very 
Nm is yet known of the primary flora of the higher parts of Celebes. This remark applies 
more or less to Buru, Halmaheira, Ceram, and the other islands west of the line which 
separates Warburg's “Papuasian” flora from the flora of * Malesia" (Warburg, in Engler, 
Bot. Jahrb. xiii. (1891) 230 e£ segg.). It is very probable, for geological reasons, that the 
line separating the Malayan and the Austro-Malayan floras will be found to lie much 
‘nearer to Warburg's line than to Wallace's ; but I believe its exact course will appear to be 
almost as indefinite and practically arbitrary as, for instance, the line which separates the 
Malayan and the tropical Himalayan floras. There will "ay: be a wider or narrower 
strip of borderland between the two divisions. Where it consists of recent land, and 
partieularly of land of low elevation and of cleared land, it will bear the more universal 
character of the insular Indo-Malayan flora ; where it comprises primitive and undisturbed 
land it will naturally be rich in endemic elements, and it will approximate more or less to 
the typical Malayan or to the typical Austro-Malayan character, according to the position 
SECOND SERIES.—BOTANY, VOL. IV. R 
