CHAPTER XII. 
THE ORIENTAL REGION. 
THIS region is of comparatively small extent, but it has a very 
diversified surface, and is proportionately very rich. The de- 
serts on the north-west of India are the debatable land that 
separates it from the Palearctic and Ethiopian regions. The 
creat triangular plateau which forms the peninsula of India is 
the poorest portion of the region, owing in part to its arid climate 
and in part to its isolated position ; for there can be little doubt 
that in the later Tertiary period it was an island, separated by an 
arm of the sea (now forming the valleys of the Ganges and 
Indus) from the luxuriant Himalayan and Burmese countries. 
Its southern extremity, with Ceylon, has a moister climate and 
more lyxuriant vegetation, and exhibits indications of a former 
extension southwards, with a richer and more peculiar fauna, 
partly Malayan and partly Mascarene in its character. The 
whole southern slopes of the Himalayas, with Burmah, Siam and 
Western China, as well as the Malay peninsula and the Indo- 
Malay islands, are almost everywhere covered with tropical 
forests of the most luxuriant character, which abound in varied 
and peculiar forms of vegetable and animal life. The flora and 
fauna of this extensive district are essentially of one type 
throughout; yet it may be usefully divided into the Indo- 
Chinese and the Malayan sub-regions, as each possesses a 
number of peculiar or characteristic animals. The former sub- 
region, besides having many tropical and sub-tropical types 
of its own, also possesses a large number of peculiarly modi- 
fied temperate forms on the mountain ranges of its northern 
