VERTEBRATE ANIMALS IN INDIA, CEYLON, AND BURMA, 681 
countries but notin the Himalayas or Northern India. In connection with this 
the limitation of the Dravidian element to the south of India should also be 
remembered, Then there is the occurrence of certain Himalayan species on 
the mountains of Southern India and Burma, and even farther south, but not 
in the intervening area, There isalso the predominence of the Western, or 
what I have proposed to call the Aryan, elementin the Pleistocene fauna of 
the Nerbudda Valley, and of Karnul in the north of the Carnatic tract, Last- 
ly we have to account for the apparently recent immigration of Oriental 
types into the Himalayas, 
Whilst it is quite possible that other explanations may be found, it is evident 
that all these peculiarities of the Indian fauna may have been due to the Glacial 
epoch. The great terminal moraines occurring at about 7,000 feet in Sikhim, 
first discovered by Sir J. Hooker ;* whose observations have been confirmed by 
myself} and others, and the occurrence of similar moraines and other indica- 
tions of ice action at even lower levels in the Western Himalayas, f{ clearly 
show that the temperature of the mountain range must have been much lower 
than at the present day when no glacier in Sikhim is known to descend much 
below 14,000 feet. 
During the coldest portion of the Glacial epoch, a large part of the higher 
mountains must have been covered by snow and ice, and the tropical Oriental 
fauna which had occupied the range, and which may have resembled that of 
the Indian Peninsula more than is the case at present, must have been driven 
to the base of the mountains orexterminated. The Holarctic forms apparent- 
ly survived in larger numbers. The Assam Valley and the hill ranges to the 
southward would afford in damp, sheltered, forest-clad valleys and hill slopes 
a warmer refuge for the Oriental fauna than the open plains of Northern 
India and the much drier hills of the country south of the Gangetic 
plain. The Oriental types of the Peninsula generally must have been driven 
southwards, and some of them, such as Loris and Tragulus, which must origi- 
nally have been in touch with their Burmese representatives, have never re- 
turned, It was probably during this cold period that the ossiferous Nerbudda 
beds and the deposits in the Karnul caves were accumulated, The tropical 
damp-loving Dravidian fauna, if it inhabited Northern India, must have been 
driven out of the country. Unless the temperature of India and Burma 
generally underwent a considerable diminution, it is not easy to understand 
how plants and animals of temperate Himalayan types succeeded in reaching 
the hills of Southern India and Ceylon, as well as those of Burma and the 
Malay Peninsula. 
When the whole country became warmer again after the cold epoch had 
passed away, the Transgangetic fauna appears to have poured into the Hima- 
* ‘Himalayan Journals,’ vol. ii, pp. 7, &e, 
+ ‘Jour., As. Soc., Beng.,’ xl, 1871, Pt. 2, p. 393. 
+ ‘Manual of the “Geology of India,” Ed. 1, p. 873 ; Hd. 2, p. 14, and references 
there quoted. 
