CHAP. XII.] 
THE ORIENTAL REGION. 
335 
not superior, in the variety and beauty of its productions, to that 
which we have just been considering. Like Indo-China, it is a re- 
gion of forests, but it is more exclusively tropical ; and it is there- 
fore deficient in many of those curious forms of the temperate 
zone of the Himalayas, which seem to have been developed from 
Palaearctic rather than from Oriental types. Here alone, in the 
Oriental region, are found the most typical equatorial forms of 
life— organisms adapted to a climate characterised by uniform but 
not excessive heat, abundant moisture, and no marked departure 
from the average meteorological state, throughout the year. These 
favourable conditions of life only occur in three widely separated 
districts of the globe — the Malay archipelago, Western Africa, 
and equatorial South America. Hence perhaps it is, that the 
tapir and the trogons of Malacca should so closely resemble those 
of South America ; and that the great anthropoid apes and crested 
hornbills of Western Africa, should find their nearest allies in 
Borneo and Sumatra. . 
Although the islands which go to form this sub -region 
are often separated from each other by a considerable ex- 
panse of sea, yet their productions in general offer no greater 
differences than those of portions of the Indo-Chinese sub- 
region separated by an equal extent of dry land. The ex- 
planation is easy, however, when we find that the sea which 
separates them is a very shallow one, so shallow that an eleva- 
tion of only 300 feet would unite Sumatra, Java, and Borneo into 
one great South-eastern prolongation of the Asiatic continent- 
As we know that our own country has been elevated and de- 
pressed to a greater amount than this, at least twice in recent 
geological times, we can have no difficulty in admitting similar 
changes of level in the Malay archipelago, where the sub- 
terranean forces which bring about such changes are still at 
work, as manifested by the great chain of active volcanoes in 
Sumatra and Java. Proofs of somewhat earlier changes of level 
are to be seen in the Tertiary coal formations of Borneo, which 
demonstrate a succession of elevations and subsidences, with as 
much certainty as if we had historical record of them. 
It is not necessary to suppose, nor is it probable, that all these 
