I.—INTRODUCTION. 09 
dense forest, the constituent species of which are those that oceur 
on the lower slopes of the mountains themselves. In existing 
river-beds only a few tough flexible bushes oceur; along abandoned 
shingly river-courses the jungle is open and park-like, and the spe- 
cies are those characteristic of a drier climate than obtains in the 
forest alongside. This submontane forest is normally succeeded 
by a belt of swampy land of varying width, covered with long 
reedy grasses. Further out into the plain the ground as a rule 
rises somewhat, and, if so high as to be free from inundations, 
is in waste tracts’usually covered with open jungle—of a bushy 
character in the western parts, taller and more park-like in the 
bushes and trees, that form characteristic village shrubberies. In 
the western parts of this area, where the population is very dense, 
these village shrubberies are sparingly represented ; further east, 
the thickets thus formed become as a rule larger and denser ; in 
places where a population has formerly existed, but has now dis- 
appeared, the species characteristic of these village shrubberies 
form dense and sometimes, as on the site of Gour, rather extensive 
forests. 
owards the west, the tracts liable to inundation are mainly 
confined to the banks of the larger rivers, and are there often 
covered with a jungle of reeds and bushes, largely Tamarisk, with 
a few trees. As we pass further east, however, the river-courses 
widen considerably in proportion to their streams, and their beds 
contain little or no vegetation. The powerful current in the rains 
sweeps everything away; the shingly or sandy banks are at other 
seasons too dry to admit of much growth. But old river-beds, 
marshes, lakes, and such streams as are stagnant or nearly 80, 
except after heavy rains, are almost as completely covered with 
vegetation as is the land, while even small rivers with a gentle 
stream abound with water-plants. The south-eastern portion o 
North Bengal and that portion of Central Bengal to the east of 
