164 
The Philippine Journal of Science 
1916 
TABLE XIX. 
Doona. 
Stemonoporus. 
VC 
. 0 
0 
c 
. i 
0 
RC 
. i 
0 
RR 
. 2 
2 
R 
. 4 
4 
VR 
. 3 
9 
11 Marks 51 
15 Marks 82 
Rarity 
. 4.6 
5.4 
And page 324, 
TABLE XX. 
Number. 
Marks. 
Rarity. 
Species of wide distribution. 
1,508 
4,579 
3.0 
Species confined to Ceylon 
and 
Peninsular India 
492 
1,714 
3.48 
Mean rarity of all 
3.49 
Species endemic to Ceylon 
809 
3,518 
4.3 
Species of all 23 endemic genera.. 
52 
236 
4.5 
Specie's of Doona 
11 
51 
4.6 
Species of Stemonoporus 
15 
82 
5.4 
Such figures as these no ingenuity can torture into any kind of support 
for a theory of development of endemics to suit the local conditions. 
These figures likewise throw no great light on the multiplica- 
tion table, but do not therefore impair its validity nor jeopardize 
its general acceptance. For the understanding of this situation, 
it is not natural selection nor multiplication, but division, the 
effects of which need to be understood. There is no question 
that in the Philippines the commonest timber trees are the lauans, 
likewise dipterocarps, but there is a considerable number of 
species of lauans, and individually they are not exceedingly 
common. As to Ceylon dipterocarps, note the expression 7 
“The Dipterocarpaceae, so common in Ceylon * * *.” If 
Dooyia had a single species, it might be very common, and 
Stemonoporus might be common, or very common, if it were 
monotypic. There are no figures by which to decide how many 
times “very common” must be divided in order to produce “rare,” 
but any man who has ever seen an apple divided knows that 
the portions are smaller than the whole. If Doona and Stemono- 
porus were as a whole only as common as other genera or as 
the mean of all Ceylon plants, then the fact that Doona is split 
into eleven species and Stemonoporus into fifteen would suffice 
7 Ann. Roy. Bot. Gardens Peradeniya 4 (1907) 18. 
