56 



AGE AND AREA 



[PT. 



endemics showed that they were found upon areas of various 

 sizes up to the full extent of the dry or the wet zone of Ceylon, 

 or more rarely of both, but that the numbers grew smaller as 

 one went up the scale toward the larger areas, Trimen in his 

 Flora had rendered yeoman service to the student of areas, by 

 attaching to every species a note to the effect that it was Very 

 Common (VC), Common (C), Rather Common (RC), Rather 

 Rare (RR), Rare (R), or Very Rare (VR). A study of the 

 localities in which species had been found showed that as a rule, 

 though with a good many exceptions, a VR species oeoirred in 



ioon«tles 



one place only, or two close together, R in an area about 10-30 

 miles across, RR in one 30-60 miles across, and RC and C in 

 areas larger yet, while VC referred rather to unusual common- 

 ness on areas represented by C. • 



The three diagrams here reproduced give the ranges of a 

 number of the earlier endemic species in Trimen 's Flora of 

 Ceylon, belonging to the classes VR, R, and RR. The VR species 

 are, it will be seen, usually well localised, though a few (5 in the 

 diagram) have been recorded from two widely separated localities, 

 joined by a wavy line. The R and the RR species, however, 

 cover areas that overlap one another in every jDossible way, and 

 look something like the rings in a shirt of chain mail. Nowhere 

 do the areas occupied by two endemic species coincide, except 



