10 ORIGIN OF LIFE IN AMERICA 



led him to a comparison of the fossil hare remains from the 

 ossiferous fissures of Ightham in England with the recent 

 polar or arctic hares as a whole. He has been exceptionally 

 fortunate in disposing of large osteological collections, and 

 his conclusions are of particular interest and of much value 

 in elucidating some important zoogeographical problems. 

 Dwelling upon the close affinity existing between the English 

 fossil and the Irish living arctic hare, he regards the latter 

 as the direct descendant of the former. 1 should not have 

 mentioned these particulars except that they give rise to far- 

 reaching deductions. From the fact of the fossil English and 

 recent Irish forms being the least specialized members of the 

 whole group of arctic hares, Mr. Hinton concludes that it is 

 highly improbable that the group can have had a boreal 

 origin.* 



That the Irish, arctic hare has always lived in Ireland under 

 temperate conditions is an opinion which I expressed long 

 ago in my works on the European fauna, and in this view Mr. 

 Hinton concurs. But I also believe, as I shall endeavour 

 to demonstrate later on, that even southern Greenland and 

 all the lands surrounding the north Atlantic had a milder 

 climate during the Pleistocene Period. It is principally the 

 climate of arctic America and Greenland, I think, that be- 

 came much more unfavourable within recent geological times, 

 while that of the British Isles has undergone comparatively 

 little alteration. Meanwhile specialization among the animals 

 constituting the Greenland fauna probably proceeded at a 

 more rapid rate than in Ireland, where the hare had no need 

 to become adapted to different "conditions of food 'and tempera- 

 ture. In spite of Mr. Hinton's -argument, I still believe in the 

 arctic origin of the group in Pliocene times, mainly because I 

 do not admit that we have any evidence for the assumption 

 that Ireland was connected with Great Britain during or 

 after the Pleistocene Period. Mr. Hinton thus differs from 

 me in regarding Central Asia as the centre of origin of the 

 arctic hares in Pleistocene times. 



I mentioned that the banded lemming (Dicrostonyx tor- 

 quatus) was found in Greenland. Of late years it has been 



* Hinton, M. A. 0., " The fossil hare of Ightham," pp. 263264. 



