4 BENGAL PLANTS. 
system to adopt, because the most practicable, must be one that is 
based on a frank recognition of existing political frontiers, no 
matter how unscientific these may be. Now and again, however, 
it may be found possible, and indeed advisable, to effect a com- 
promise, at least in matters of detail, between these political 
frontiers and the boundary lines indicated by the natural facts 
of distribution. 
n the case of the Lower Provinces—for the use of whose 
inhabitants the present work is designed—a compromise of this 
kind seems particularly desirable. Here are included the plants 
of Bengal, Behar, and Tirhut, or those of the eastern half of the 
Gangetic plain, and those of the Sundribuns or the Gangetic delta. 
Besides these, however, the work includes not only the plants of 
Chota Nagpur and of Orissa, which are almost wholly character- 
istic of Coromandelia, but those of Tippera and Chittagong, which 
are Indo-Chinese rather than Indian, With the exception of a 
single district the work deals with the whole of the territories that 
go to form the Lieutenant-Governorship of Bengal, irrespective of 
the natural areas completely or partially included in its various 
provinces. The excluded district is that of Darjeeling, which, 
save as regards the submontane subdivision of Siliguri, is wholly 
Himalayan, and, from an elevation of 1500 feet upwards, possesses 
of any other two districts. To include in our Bengal list the 
plants of the Darjeeling district that are distinctly Himalayan — 
would necessitate a larger volume, while the increase in bulk 
would confer no corresponding benefit on, indeed it might con- 
ceivably prove a hindrance to, some of those who are likely to use 
it. It seems preferable, therefore, to prepare a separate list of the 
plants of the Darjeeling district. If it be objected that the course 
now followed involves the exclusion from the Bengal list of the 
plants of the Sikkim Terai, which naturally forms part of the 
northern extension of the Bengal plain, the answer is that the 
corresponding tract to the east of the River Tista, known as the 
Duars, is within the area here discussed, so that no species foun 
in any part of Bengal is likely to be omitted from the list. If it 
be further objected that the inclusion of the plants of the Terai and 
of the lower hills and valleys of Sikkim in a subsequent Darjeeling 
