682 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. X111. 
layas from the eastward, At the present day the comparatively narrow Brah- 
maputra plain in Assam is far more extensively forest-clad, especially to the 
eastward, than is the much broader Gangetic plain of Northern India, and if, 
as is probable, the same difference between the two areas existed at the close 
of the Glacial epoch, it is easy to see how much greater the facilities for the 
migration of a forest-haunting fauna must have been across the Brahmaputra 
Valley than over the great plain of the Ganges. This difference alone would 
give the Transgangetic fauna of Burma an advantage over the Cisgangetic 
fauna in a race for the vacant Himalayas, even if the latter had not been 
driven farther to the southward than the former, as it probably was during 
the Glacial epoch. 
The theory, however, is only put forward as a possible explanation of some 
remarkable features in the distribution of Indian vertebrates. At the same 
time, it does serve to account for several anomalies of which some solution is 
necessary. If thus accepted, it will add to the evidence, now considerable, in 
favour of the Glacial epoch having affected the whole world, and not having 
beena partial phenomenon induced by special conditions, such as local 
elevation, 
(The above paper was read before the Royal Society on 13th December, 1900, 
and appeared in the Proceedings of the Society in Vol, 67.) 
