160 TEST CASES [ch. xiii 



Other genera, e.g. Amoora, Celastrus, Hippocratea, Leea, Limacia, 

 OIcLV, Salacia, Tinospora, Zizyphus, from the first volume of 

 Hooker's Flora, show the same thing. Clarke (4) says that in 

 the Himalaya closely allied species of Didymocarpus are confined 

 to single districts, though there appears no reason in soil or 

 climate why they should not spread to adjoining valleys. 



Now to explain such phenomena as these by aid of natural 

 selection is very difficult. The range of the wide-ranging Anemone, 

 for example, is put down to its "adaptation", though to what 

 exactly it is adapted is not explained. If it suit (as it does, place 

 by place) the very varied range of conditions in which it is found 

 that must be due to functional or physiological adaptation as it 

 moved from one region to another. We have no evidence that a 

 seed from say Ceylon would at once suit a station in the north- 

 west Himalaya, without first acquiring the necessary local adap- 

 tation which it would have received as a matter of course had it 

 been slowly transported from place to place by nature's method. 

 But it would then, in all probability, cease to be fully suited to the 

 Ceylon habitat. But why should it be accompanied by eleven 

 local species? All these are endemic to their own regions. In 

 their anxiety to disprove my contention that such local endemics 

 are young species as compared with the wide-rangers, my 

 opponents have gradually pinned their faith to relicdom. But 

 why should A. rivularis leave eleven defeated relics in its range 

 of distribution? It looks as if selection had been very strenuous, 

 and was greatly diminishing the number of species, not increasing 

 it (p. 90). There is absolutely nothing to prove that any of them 

 are relics, and no feature in A. rivularis that gives even a faint 

 suggestion that it may be adaptationally superior. It covers all 

 the mountains of India and Cevlon, and whv are there no local 

 relics in any of the southern mountains? None occur south of the 

 Khasias. But there can be little doubt that Anemone advanced 

 from north to south in the Indian region, reaching Ceylon last of 

 all, so that it would be younger in the south than in the north. 

 By the theory of age and area, its peculiarities are at once ex- 

 plained. A. rivularis arrived first somewhere in the Himalaya, 

 where only the local endemics are to be found, and it has not been 

 long enough in the southern mountains to mutate off new en- 

 demics there. The relic explanation is altogether too fanciful to be 

 accepted, as is also that of local adaptation, which also will not 

 explain the crowding together of the endemics in the north. 

 Nothing hitherto proposed with the exception of age and area 



