with reference to the Dying Out of Species . 9 
Only two genera in this list ( Vernonia 3-3 and Sctccolabium 3-4) are equal 
to or above the average in point of rarity. 
One may even go lower than this, and take the genera with fewer than 
five species. Naturally any one genus may show any figures from VC 
to VR, but if one add them together in groups one gets the same result 
as before. We may take all the genera beginning with one letter of the 
alphabet, and get, 
Table VIII. 
VC 
C 
RC 
RR 
R 
VR 
3 Rarity . 
Beginning with A 
3 
9 
11 
11 
12 
11 
3*9 
B 
— 
4 
5 
2 
10 
4 
4-2 
C 
— 
5 
10 
11 
13 
2 3 
4«6 
D 
— 
1 
4 
5 
3 
9 
4-6 
3 
19 
30 
29 
38 
47 
There is no need to follow the comparison through the whole alphabet. 
It is sufficiently obvious from all these tables that the distribution of the 
species of the various endemic families and genera obeys a simple law 
which determines that the numbers under the different heads from VC 
to VR shall be distributed in proportions increasing from the former to the 
latter. The numbers simply vary about the suppositional numbers in 
the ordinary way of trial and error. The maximum is always or nearly 
always at VR, 
If one analyse the same tables as to the figures for the Ceylon-Indian 
and widely distributed species, one finds exactly similar results, but with 
the maxima differently placed. For instance, the first five orders (i.e. in 
number of endemics) show, 
Table IX. 
Orchidaceae 
Rubiaceae 
Dipterocarpaceae 
Euphorbiaceae 
Acanthaceae 
Total 
Ceylon-P. - India . 
1 6 9 10 5 8 
653 641 
484 334 
1 7 7 4 7 4 
12 26 24 23 19 17 (121) 
Wide. 
1 6 12 8 14 4 
7 13 9 5 6 2 
4 26 8 7 8 6 
7 9 5 2 ~ 1 
19 54 34 22 28 13 (170) 
For convenience it will be well to arrange these together with the endemics, 
thus : 
Table X. 
VC 
C 
RC 
RR 
R 
VR 
Total. 
Endemics 
6 
14 
49 
44 
57 
63 
233 
Ceylon-P.-I. 
12 
26 
24 
23 
19 
i 7 
121 
Wide 
19 
54 
34 
22 
28 
13 
170 
Whilst the maximum of the endemics lies at VR, that of the Ceylon- 
Peninsular-Indian species lies at C, with no very great tailing off towards 
VR, and that of the Wides lies very markedly at C, with an immediate 
and sudden drop to RC and RR. 
