94 Journal of the Asiatic Society of Bengal. [N.S., XIX, 
that the shales are jreqguently more rubbly and 
non-sandy. 
The acing rocks—which attain a thickness of at least 
5.000 feet—are usually but slightly folded and give rise to 
eae or undulating tracts of soft sands. The lower-lying 
parts are extensively covered with alluvium. The hard beds 
of the Lower and Upper Groups of the Pegu give rise to lines 
of hills and the rocks are often highty folded. The shales of 
the Middle Group give rise to extensive low-lying or gently 
undulating tracts—frequently the most infertile in Burma. 
he Pega System reaches an enormous thickness, not less than 
The normal Irrawadian sands yield a very light soil— 
practically a pure sand but on ae plateau- -surfaces there 
is a marked concentration of the iron salts near the surface 
and a hard ‘ pan p 
Meare: of prime ca The = groups of the Pegu 
roup “spproach more closely the soils of the middle group. 
Provided the rainfall is not less than 36 inches the middle 
shales oka g into a stiff blue clay. When, however, the 
rainfall falls bole about 36 inches a type of weathering sets 
in which produces a soil known to the Burmans as “ Hput- 
tration of alkaline salts, especially of sodium carbonate, In 
the surface layers and only the most alkali-resisting plauts 
can possibly grow. The alluvium of the River Irrawaddy 
furnishes the usual Burma paddy soil—a heavy loam. Chaung 
allluvium meee Hill-wash partake of the nature of the rocks 
from which they are derived, with a marked amelioration 
of the ssHcat features of the latter 
lil. GenerRaAL REMARKS ON THE VEGETATION AND 
EpapuHic ContTRrRoL 
The climate of Burma is essentially a woodland climate. 
Apart from the sandbanks and some of the recent a. 
which are covered with the well-known “ Kain “ Ele 
phant”’ grass there are no areas of true grassland in > Central 
Burma. Even then the Kaing Grassland must be regarded 
as a seral or non-climax community,—i.e. it has not reached 
the final condition which it a normally attain under 
the existing climatic condition 
Schimper has stated that tropical eed enn earn 
are of four main types:—Rain Forest, Mon Forest, 
Savannah Forest, and Thorn Forest. “this eve grouping 
