INTRODUCTION 3 
extend in broken sequence from the south of the 
Peninsula, to cease in the north at that point where 
elevation is prohibitive of tree growth; and they 
still exist in large or small patches from Kashmir in 
the west to the border of Siam; they cover an area 
of one fourth of the Empire, and some 240,000 | 
square miles are, in British India, the property of | 
the State, the remainder being within the boundaries" 
of native principalities. As might be expected in a 
country that extends from the region of perpetual 
snow to within 8 degrees of the Equator, the varia- ' 
tions in forest growth are as great as those of 
temperature; but there are other conditions which 
exert even a greater influence than temperature, 
the chief of these being the average amount of rain- 
fall that is annually received. It would be possible 
to divide the whole of India into numerous zones 
dependent on the amount of rainfall each enjoys, 
but this is not a botanical treatise, and for general 
purposes it will suffice to say that where the rainfall 
is below 20 inches the dry forests can alone exist, 
that from 20 to 70 inches suits the deciduous forests, 
and that where more than 70 inches of rain falls| 
the evergreen forests flourish. Thus, in Sindh and | 
Rajputana the first type may be observed; the 
second occupies nearly the whole of the central 
portion of the Peninsula; while the third is found in 
the West Coast of Madras and in Burma. The hill, 
tidal and riparian forests possess characteristics 
governed, in the one case, by elevation, and, in the 
others, by the tides and river floods that nourish 
them, and they are to be seen at their best re- 
spectively in the outer ranges of the Himalaya, on 
