THE GLACIAL RANGE CONTRACTION, ETC. 139 



mammalian fauna of Ireland agrees more closely with 

 that of Scotland than of England ; while Dr. Buchanan 

 White has shown that Ireland has probably derived 

 some of its alpine lepidoptera from Scotland. We ma\- 

 suppose that the temperate mammals gained admittance 

 to Ireland from the west of Scotland, between which 

 and the north of Ireland there was a broad land con- 

 nection. Some of the larger mammals, however, such 

 as the great Irish deer {Cervus mcgaccros), may quite 

 well have entered Ireland from the south, crossing the 

 river that flowed south through St. Georges Channel. 

 But it may be questioned whether the reindeer immi- 

 grated by the same route. So far as the geological 

 evidence goes, we have no reason to believe that at the 

 commencement of the Post-Glacial period the British 

 area was much more extensive than it is at present. 

 The sea was then retiring, as we know, from the low 

 grounds of Scandinavia and Scotland, and from the 

 borders of East Anglia, and thus the probabilities are 

 that when the Scandinavian flora had commenced its 

 northward advance St. Georges Channel still separated 

 England and Ireland. This being so, the reindeer 

 could not at that time reach the latter country. B}- 

 and by, however, the Irish Sea gradually disappeared, 

 and a land connection took place between Scotland and 

 Ireland, across which the alpine and sub-alpine flora and 

 the reindeer would migrate [emigrate]. It is perhaps 

 owing to the late appearance of this land connection 

 that the Scandinavian type of vegetation is so poorly 

 represented in the Hibernian flora. The climate we 

 may suppose Avas already becoming milder, and the 

 high alpine forms were graduall}' vanishing from the 



