SPECTKS BY IT^FTN^TTKSIMAI. VARTATTOT*^. 11 



Now, why should the common ancestor in one country give rise 

 to A and B , in the other country to A and C ? In the Eastern 

 Peninsula, again, live D. ovafa and D. meliosmcefolia , as well 

 as D. indica, and these species are closely allied. Why should 

 they be better suited to the Eastei-n Peninsula, while D. brac- 

 teata suits Mysore and D. retusa Ceylon ? 



In Unona, again, what advantage can the deep constriction 

 between the seeds of U. elegans be to it, as compared with the 

 slight constriction of U. zeylanica? 



Or what advantage can the two ovules of Polyalthia Moonii 

 and P. persicifolia be against the one of the other species ? 

 P. rufescens, another species witli two ovules, and closely 

 allied to both, occupies the Cocliin District of South India, 

 and why should there be three species in so similar a country, 

 especially as the Ceylon species live in the same district? 

 And how did the one form get to the other, or both arise 

 from a common ancestor, except by mutation i 



Similar queries might b6 asked 800 times for the 800 

 endemics comprised in the Ceylon flora, but these few must 

 suffice, as we do not wish to labour the point. 



Now, where the endemics are confined to a small local area, 

 and are not accompanied by their nearest related species, it 

 is still possible to say, though the argument is but a weak one, 

 that they may have been ev^olved to suit the local conditions, 

 but how is this argument to apph^ when the two grow close 

 together, as in fact is very commonly the case in Ceylon, 

 and was for instance the case with the Coleus species on the 

 top of Ritigala ? 



For if the endemic species had developed its peculiarities 

 to suit the local conditions, one would expect that the other 

 species would not suit them. But it not infrequently happens, 

 as in the case of the Dillenias mentioned above, that there 

 is one common and widespread species, accompanied 

 here and there by a local species confined to one district. 

 To take an example from the families alreadj^ considered, 

 in Uvaria there are two nearly allied species, U. Narum and 



