XXX 
INTRODUCTION 
Genera 
Species 
Orders 
Simla 
District 
British 
Islands 
Simla 
District 
British 
Islands 
Commelinaceae . 
3 
0 
6 
0 
Juncacese 
2 
2 
7 
4 
Araceae 
6 
1 
11 
1 
Lemnaceae 
2 
2 
4 
4 
Alismaceae 
1 
1 
1 
1 
Naiadaeeae 
3 
3 
8 
6 
Eriocaulaceae 
I 
1 
3 
0 
Cyperaceae 
12 
5 
56 
2 
Gramineae 
58 
21 
133 
21 
Totals 
123 
639 
244 
1326 
173 
Dicotyledones 
Monocotyledones 
Petaloideae . 
Glumaceae . 
Gymnospermae 
Summary 
Genera Species 
. 498 or 78*0 per cent. 1003 or 75 -8 per cent. 
| 133 or 20*8 „ jg* } 313 or 23*3 
. 8 or 1*2 „ 10 or 0*9 „ 
639 100 1326 100 
The proportion of species of Dicotyledones and Monocotyledones 
in the flora of the world is about 81*30 and 18*70 per cent., and the 
23*3 per cent, of Monocotyledones in Simla is very high. It is due in 
this instance to the large number of grasses in this comparatively 
small area. For the whole of India the percentage is 23*43, and 
for other large areas that I have calculated it varies from 17*30 
in Europe ; 18*50, Australia ; 19*38, North America ; to 21*50 in 
Mexico. 
From the foregoing comparison of the floras of the Simla 
District and the British Islands it will be understood that a person 
having some knowledge of the latter will be well prepared to take up 
the study of the former. It is true that only about 13 per cent, of 
the species are the same ; but nearly 40 per cent, of the genera are 
common to the two countries. Incidentally it may be mentioned 
that in higher latitudes the resemblances become stronger. Thus 
in a collection of about 500 species from the neighbourhood of 
Kirin, in about 126° E. long, and 44° N. lat., 160 were British, or 
just 32 per cent, of the whole. 
On the other hand, it is somewhat surprising to find that thirty- 
eight Natural Orders are represented in the small district of Simla 
which are not included in the flora of the British Islands. This is 
