14 WILLIS : EVIDENCE AGAINST THE ORIGIN OF 



Why should the double allowance of stamens in Toddalia 

 lanceolata fit it to live alongside of T. aculeatn ? 



Or, to turn to the flora of New Zealand, why should the 

 stemless form, and spatulate leaves, of Cardamine depressa 

 fit it to inhabit the same places as the stemmed C. hirsuta witli 

 pinnate leaves ? Or, why should the subcordate leaves of 

 Hypericum gramineum fit it to live alongside of the oblong- 

 leafed H. japonicum ? 



Examples like these might be multiplied to any extent by 

 taking other floras, but these must suffice for the present. 



But to the whole of the line of argument adopted in the 

 last paragraphs it may be objected that the two species quoted 

 are not, so to speak, parent and child, but both descended 

 from a common ancestor. To this I would reply, how can 

 the existence of numerous endemic species, all closely allied 

 to one common species, and all separated by some distance 

 from one another, be explained on any but the parent and 

 child theory ? Take the Indian flora as an example.* To 

 begin again at the beginning, in the genus Clematis, § Cheirop- 

 sis, we have C montana common all along the Himalaya, 

 while C. napaulensis, C. barbellata, and C. acutangula are 

 confined to particular sections. We have Aiiemone rivularis 

 common throughout the Himalaya, and various local allied 

 species. And many more examples of the same kind might 

 be quoted, but this must be reserved for a later paper. The 

 general principle on which India and Ceylon have been peopled 

 with the many species which they contain would seem to be 

 that one very common species has spread widely, and, so to 

 speak, shed local endemic species at different points, or else 

 that one species has spread, changing at almost every point 

 into a local endemic species, which has again changed on 

 reaching new localities. 



This must suffice as a preliminary statement of the position 

 taken up, which is that the evidence of endemic species 



* This theory explains some of the puzzles of geographical distri- 

 bution with ease, as I shall show in a subsequent paper. 



