HiNT0N~7%e Fossil Hare of the Ossiferous Fissures of Ightham. 265 



The moral which I wisli to draw is perhaps pointed by the fact that, 

 although many attempts have been made to introduce L. eurojjmis into 

 Ireland, they have all proved more or less unsuccessful.' One may be 

 tempted to ascribe the failure to some climatic difference, although it is 

 difficult to quite imagine what such a difference may be. The early 

 separation of Ireland from Britain, which has kept Ireland free from 

 Z. euro^oceus, may also have kept out of the latter country some other 

 organism whose presence is essential to the prosperity of the common 

 Hare or inimical to that of the Irish Hare. If one could find out exactly 

 what this factor is, and succeed in introducing it into Ireland, one miglit then 

 succeed in introducing L. eurojxeiis. In the latter case L. variabilis would, 

 judging from what has happened in England and elsewhere, rapidly lose 

 ground. 



The moral itself is that, however tempting the idea of great changes of 

 climate may be as affording a ready explanation of the changes which have 

 taken place in the distribution of animals and plants since the Pleistocene 

 period, or since a still more remote time, we should not adopt it without 

 considering whether or no the organisms themselves, by their own interaction 

 and interdependence, can have produced the modifications which they have 

 suffered both in their habitats and in their structure. It might be put even 

 higher, namely, that the palaeontologist should not dream of changes of 

 climate and the like until he is satisfied that the organized part of nature is 

 incapable of working out its own destiny. There can be no doubt that the 

 relations existing between the elements of a fauna and flora are of the most 

 complex kind, the right appreciation of which can only come to us as the 

 reward of the most patient investigation in the future ; and therefore, having 

 regard to our present ignorance, it does seem a little arrogant to say that 

 this or that case transcends the capabilities of organic nature, and that 

 consequently we must attempt to explain it by burdening the equation with 

 other powers still more difficult to comprehend and still more far-reaching in 

 their effect. 



' Barrett-Hamilton, Irish Naturalist, vii., 1898, p. 69. 



SCIENT. PKOC. R.D.S., VOL. XH. , NO. XXHI. 



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