DISTRIBUTION OF BIRDS IN CEYLON. a7 
awkward complications on the “‘ Carnatic” side of the Island, 
we must argue that the present connection vid Adam’s Bridge 
was then under the sea, or relatively more than 3,000 feet 
lower than at the present day. 
Now, depressions and elevations of the earth’s surface are 
not the result of sudden spasms, but are due to infinitely 
gradual processes of long duration, and although an earth 
movement of 3,000 feet is far surpassed by many on record, 
a change of such large vertical measurement would be spread 
over a wide area. Consequently, one cannot invoke at will a 
fairly sudden change of over 3,000 feet in level between 
Tuticorin and Colombo dying away to nothing along the axis 
of Adam’s Bridge unless there is geological evidence to support 
it. In the present case there is no such evidence on record ; 
in fact, the nature of the sea basin in the Gulf of Mannar is all 
against the assumption of such a large movement within such 
recent geological times. 
If, however, the climatic conditions during the glacial 
epoch are considered, it is quite possible the connection 
required to bridge the gap may have lain along the present 
shallow belt of sea—which is nowhere more than seven 
fathoms deep—extending from Adam’s Bridge for at least 
fifty miles to the north. 
The present arid condition of our “ northern maritime 
belt ”’ and the opposite Indian coast is no doubt intensified 
by the sterile nature of the soil : a wide stretch of sand recently 
covered by a shallow sea, and incapable of supporting a growth 
of heavy forest. Before its temporary submersion this tract 
may well have been country much like the central forest 
portion of the North-Central Province. We must also 
remember that during glacial times our climate, besides being 
colder, was probably also damper, as the Himalayan snow 
fields were so much more extensive. 
It is not so hard then to suppose that, given a lower tempera- 
ture when evaporation would be diminished, and probably also 
given at the same time a heavier rainfall, there would be a 
continuous stretch of forest damp enough to allow free inter- 
course for a Malabar type of fauna between the Malabar coast 
and the south-west of Ceylon. 
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