i) 
fu) | 
rey 
MR. W. B. HEMSLEY ON THE 
| Species. 
Species. | Brought up .. 96 
SAUSSUTED . vc cence ene 15 | Nepeta oe. cece eevee ees 6 
Sedum vivccvcceccceees 9 | Carer’ civivcvseveeveee 6 
Artemisia... cece nceeee QD) POd vececcec eevee eeeee 5 
Genttand oc cc vecceeves 9 | Stipa... cece cece eee ees 5 
Ranunculus co.cc eevee 8 | Delphinium wivrecceeee- 4 
Astragalus vice cece ees 8 | Corydalis vo... cece e ees 4 
Polygonum ..cccscveeee 8B | Draba vice ccc eee ee 4 
OxytrOpts vec cccceccenes 6 | Parryd .icccccee ccc eeee 4 
Potentilla oo... 6.05. wee GO | Avenaria .occise cece eee 4 
Sarvyfrdga vcveccvceveees 6 | Taravacum ...ceee eens 4 
AStEr oe cece teens 6 | Elymus... ccc eee 4 
Pedicularis ...csseeeuee 6 | Festuca oi... cece eee eee 4 
96 Total . 150 
| 
} 
These figures show that twenty-four (or 20°1 per cent. of the 
total) genera furnish 150 (or 50°3 per cent. of the total) species. 
Against this there are sixty-eight genera each represented by 
only one species. In other words, 57-1 per cent. of the genera 
yield only 24 per cent. of the species. It will be seen that 
the percentages in these two comparisons are almost exactly 
reversed. 
Species. 
The ultimate elements or components of the flora, so far as we 
subdivide, are species of unequal value, it should be remembered, 
both as to distinctness from other species and individual repre- 
sentation in the vegetation. Two hundred and eighty-three 
species is indeed a small number in so large an area; and the 
question naturally arises, why is it so restricted? But before 
attempting an answer to this question we will give some of the 
more striking particulars concerning these 283 species *. It has 
been shown that there is not a genus of flowering plants that is 
strictly endemic, or peculiar to Tibet; and very few indeed are 
endemic in a wider area embracing the contiguous countries 
* It should be mentioned here that slight discrepancies may possibly exist in 
the figures given in various parts of this paper in consequence of some of 
the latest corrections not having been made all through; but there are very 
few, if any, and they can affect no question of importance. 
