116 DR. O. STAPF ON THE FLORA OF MOUNT KINABALU. 
their northern congeners, although everything seems to point to a Boreal origin. 
Are they survivals from the great invasion to which the presence of so many Boreal 
types in Australia and even in the Antarctic region is due, or is their presence on Kina- 
balu and on the Owen Stanley Range the result of a partial re-migration of Boreal 
types from the Austral-Antarctic regions? In the latter case the phylogenetic gap in 
their relations to their northern congeners might be explained by the transformation 
which the southern branch underwent after having reached the Austral-Antarctic regions. 
We might, however, just as well admit the other alternative under the perfectly justified 
assumption that the northern congeners deviated more from their ancestors than the 
southern ones, which were hardly transformed at all. It has also been suggested (Wallace, 
‘Island Life,’ p. 490) that types of this kind might form the most advanced posts of a 
migratory movement of an extraordinary extent, namely from North America by way of 
the Andes to the extreme south of South America, and thence to the Antarctic region, to 
Australia and New Zealand, and finally to Malaya. Yet the particular types to which 
I refer in this place do not show a closer affinity to North American forms. They stand 
in the same abrupt relation to them as to their congeners in temperate Eurasia. 
I will now try to summarize briefly the conclusions to which I come with regard 
to the history of the flora of Kinabalu. The highland of Kinabalu formed, at 
a period not later than the earliest part of the Tertiary epoch, a portion of a much more 
extensive highland, which was—simultaneously or in consecutive periods—connected 
with other highlands which stretched over a wide continental area extending from the 
south-eastern part of the present mainland of Asia into the Austral-Antarctic regions. 
The flora of the then highland of Kinabalu contained already all the essential elements 
which at present characterize it. At the end of this period the highland connection with 
the south-eastern portion of this continent was severed, so that no important exchange 
of temperate elements could take place any longer in this direction. Lowland connection 
may have continued still for a time, after which it also ceased. Up to this point the 
flora of Kinabalu and of the neighbouring parts of the old continent, east and west of 
Kinabalu, formed a natural unit, grown up under the influences of a common history, 
and still manifest in the broader affinities of the present floras of these areas. After the 
separation of Austro-Malaya a new period in the evolution of the floras east and west of 
the line of separation began. The differences which were, no doubt, already indicated 
now became manifest and more accentuated. The highland of Kinabalu was still in 
close connection with the remainder of Malaya and with the Philippines. Then these 
broke away, whilst the connection with West Malaya still continued, and under 
conditions which caused a considerable general uniformity of the flora of Malaya, The 
pronounced Malayan character of the flora of Kinabalu dates from this period. Then 
the Malayan land subsided or broke down, leaving an archipelago, These conditions 
. went on and reached a maximum which must have been considerably above the present 
State. Borneo itself was reduced to a group of islands, of which the highland of Kina- 
balu was one. The increasing isolation must have acted as a most powerful agent in 
the evolution of the flora. It could not add any new element to the flora, as it then was, 
but it gave it that strongly localized or individualized charaeter which still distinguishes 
