59 



c«- viJ AGE AND AREA 



^^hJ"! fT/ ^'^^ P^"*'^^- ^"^ ^^^^>^ ^^d *h^ ^"demies 

 chmb right to the summits of the hills? One would have ex- 

 pected to find them at varying heights, pursued, so to speak, 

 by the widely distributed species before whose onslaught thev 

 ivere dymg-out, instead of finding, as is not infrequently the 

 case, a great gap in elevation between the two. It sucr^e^ts an 

 unnecessary degree of alarm about the coming competitfon, and 

 further suggests that they are not so incapable of adaptation to 

 new conditions of life that they need fear it. If they can undergo 

 the great adaptive changes necessary to reach a summit of 5000 

 feet or more, they must have a very fair capacity for modifica- 

 tion, and should be able to hold their own against the intruders 

 Queries like these might be put by the dozen (131, p 351 and 

 p. 88, below), and the explanation now under consideration 

 could give no answer. Clearly the theory of dving-out was as 

 untenable as that of local adaptation, so far as the Ceylon 

 endemics were concerned. There is no doubt that a considerable 

 number of species here and there, especially within the range of 

 the glacial periods, may be looked upon as dying-out, or some- 

 times as locally adapted, but these are comparatively few and 

 tar between, and the mass of local endemics, particularly in the 

 tropics, cannot be looked upon as coming within these cate- 

 gories. 



Just before leaving Ceylon I published a Catalogue of the 

 flora (115), which rendered the task of enumerating the species 

 with their distribution a much simpler affair, and on reaching 

 Kio I began this work. Di^'iding the species into three groups— 

 those endemic to Ceylon, those found in Ceylon and Peninsular 

 India (cut off by a line from Calcutta to the north of Bombay), 

 and those with wider distribution abroad than tliis— I found 

 that the endemics were (VC 19), C 90, RC 139, RR 136, R 192, 

 VR 233, increasing fairly steadily from top to bottom of the list 



Examining the distribution in Ceylon of the species (which I 

 termed "wides" for short) that occurred outside the island to 

 a greater distance than merely into the peninsula of southern 

 India, it was found that the areas they occupied in the island 

 ■\vent in the reverse order, being (YC 221), C 402, RC 313 RR 

 209, R 159, VR 144. 



If now, leaving out of account the somewhat uncertain VC 

 class (its greater uncertainty is largely due, as already explained, 

 to the fact that it is not based on actual area occupied), we 

 number the other classes 1 to 5 (i.e. by degree of rarity, not of 



