1899] ORIGIN OF AUSTRALIAN FLORA 207 



Australian species, or of descendants from such, would to-day form 

 part of the Indian flora ? But if this be admitted, and it is only a 

 logical deduction from the facts, the theory of the predominance of 

 northern forms collapses, and the restricted area occupied by Aus- 

 tralian species must no longer be viewed as depending upon some 

 inherent inferiority to northern forms, but simply upon fortuitous 

 geographical conditions. 1 



But we are told that the Australian flora stands less high in the 

 scale and is less specialised than are the floras of northern climates, 

 and if this be true, the point I am trying to argue must at once be 

 given up. But is it true ? In what respect, it may be asked, is the 

 flora of Australia less highly specialised ? Are not most of the great 

 natural orders strong constituents of it ? Trees, some of them of 

 gigantic size, shrubs, undershrubs and herbs, parasites and saprophytes, 

 climbing and carnivorous species, flowers adapted to profit by the 

 visits of insects, and sometimes provided with a complex mechanism to 

 ensure such profit, all these are met with in Australia, In addition, 

 we have wonderful adaptations to a dry climate, and in this respect, 

 taking into account the variety of ways in which the destructive effects 

 of a scorching sun and parched soil are guarded against, the Australian 

 flora is without a parallel the world over. And if these be not 

 evidences of high specialisation, it is difficult to know where one must 

 look for such. In one respect, and in one only, is any inferiority 

 shown, namely, in the comparatively small number of seeds produced. 

 But this does not apply to the herbs, and as for the woody species, it 

 is absolutely essential that the ripening seeds be safeguarded against 

 drought, and the laying on of thick tissues to this end may well be 

 effected at some cost as regards fecundity. 



But Mr. Wallace himself gives us an instance where land adjoining 

 the, according to him, previously isolated home of the Australian flora 

 has been stocked to a considerable extent with Australian forms. As 

 I shall have something to say hereafter about this supposition, I will 

 now merely assume its truth for argument's sake. Mr. Wallace, 2 then, 

 supposes the greater part of Northern Australia, previously submerged 

 beneath the ocean, to have become dry land in the middle or latter part 

 of the tertiary period, and the area so exposed to have been colonised 

 partly by Indo-Malayan forms from the north, partly by Australian 

 forms from the south. Now, assuming with Mr. Wallace that the 

 species with Indo-Malayan facies in Northern Australia were emigrants 

 from the north, their considerable numbers prove that there could have 

 been but slight, if any, embargo upon migration from the north when 



1 Since this passage was written, Mr. C. B. Clarke has informed me, upon his personal 

 knowledge of the Neilgherries, that the success of Australian species there has been much 

 exaggerated. In spite of this, I prefer to leave the paragraph as it stands, for it shows, at 

 any rate, to what lengths an upholder of the "northern predominance" theory may be 

 inclined to go when in search of an argument to meet alleged facts hostile to the theory. 



2 " Island Life," p. 493. 



