476 Revieivs — Scharjf's Origin of the European Fauna. 



in the superficial deposits of Scotland, Scandinavia, and North 

 America.' In the same way, I think, there are few points we 

 can be more sure of than that the South-Western European fauna 

 and flora in the British Islands are more ancient than the Siberian or 

 the Arctic. If Professor James Geikie were right, it ought certainly 

 to be the other way round. But the evidence as to the climate in 

 the British Islands during the Glacial period is so contradictory, 

 the very nature of that period is so complex, that few scientific 

 subjects during this century have raised more angry discussions, and 

 none have produced a vaster amount of literature. That I should 

 help to increase the latter still more is to be regretted, especially 

 as the subject is not my own, but having been led by faunistio 

 evidence to regard this vexed problem from a side from which it 

 has hitherto received but little attention, I hope I may be excused 

 for venturing to add my own views to those already known." 

 (p. 488.) 



The author, after citing the distribution of four species of Helix, 

 belonging to the subgenus Xerofldla, which are spread over 

 almost the whole of Ireland, except in the extreme south-west 

 portion, proceeds as follows : — " That the whole Irish fauna 

 and flora could have survived on a now sunken southern extension 

 of Ireland, is, therefore, impossible. They must have remained 

 within the present boundaries of the island during the Glacial 

 period, though it is probable that it did extend somewhat more 

 to the west, south, and north than it does now, and that those 

 parts of the country stood at a relatively higher level to the 

 east; so that the Shannon and some other rivers, which now 

 drain into the Atlantic, emptied their waters into the Irish Sea. 



" The nature of the Pleistocene Mammalia of Eastern England 

 is not such as to indicate an Arctic climate in the British Islands. 

 The presence of northern forms is due, as we have seen, to an 

 immigration of Siberian animals ; but, as they lived in company 

 with southern types, many of which required an abundance of 

 green food, the winter temperature in the British Islands may 

 have been as high or higher than it is now, though with a lower 

 summer temperature, and with a copious snowfall in winter, 

 glaciers were generated in the mountainous regions. A number 

 of land and fresh-water shells are quoted by Professor J. Geikie 

 frpm the Arctic fresh- water bed on the coast of Norfolk, in evidence 

 of a rigorous climate. These are spoken of by him as high 

 northern forms; but in this he is mistaken. Everyone of them 

 are inhabitants of Ireland at present, and all but one are very 

 common. 



"But if the fauna does not indicate Arctic conditions during 

 the Pleistocene epoch in the British Islands, we are told that 

 what is known of the flora, at any rate, is such as to exclude 

 the possibility of its existing under anything but an Arctic climate. 

 The same Arctic fresh-water bed just referred to contains, besides 

 the shells, some plant-remains, and these, according to Mr. C 

 Keid, imply a lowering of the temperature by about 20° F. Yet 



