164 The Philippine Journal of Science me 



TABLE XIX. 



Doona. Stemonoporus. 



vc - o o 



C 1 ° 



RC 1 ° 



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 



Species 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 ' 

 "The Dipterocarpaceae, so common in Ceylon * * *." If 

 Doona 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. 



