106 Proceedings of the Royal Iri>ih Acadejiiy. 



" Before the end of the ' Magdalenian Civilization ' characteiistic 

 of the period, the humidity of the atmosj)here reappeared, without 

 however being accompanied by any earth movements sufficiently 

 marked to have given rise to renewed energy in the erosive action of 

 the Water-courses. 



" The Eeindeer was almost completely driven north, and the 

 Neolithic civilization came into existence everywhere. It is probable 

 however, that the phenomena were more complicated, and that in 

 addition to the great Glacial Periods already indicated, it would be 

 proper to add intermediate phases, since every day's experience more 

 strongly causes it to be recognised that the relations between the 

 morainic deposits is more or less complicated." 



(p. 1634.) — He says: "It is therefore logical to admit that 

 successive movements of emersion of the continents which took place 

 suddenly (par saccade), marked the phases of the activity of the 

 water-courses." 



Discussing the prohahility of a rapid transition from the age of the 

 Reindeer to that of the Turf hog s^ he says : ' ' Whatever may have 

 been the exact course of events in our part of Europe, the transition 

 from the regimen of great water-courses, to that of the reindeer, 

 must have taken place rapidly. Otherwise, the rivers which at first 

 caiTied only coarse gravel, would have little by little filled up their 

 principal channels with silt, as has been justly remarked by Eelgrand. 

 On the contrary, the principal channels which during the Pleistocene 

 Epoch hardly sufficed to caiTy the river floods, must have been dried 

 up suddenly, thus layiag bare the horizontal sur-face of gravel over 

 which a thin stream continued to meander. Consequently, when 

 later on, a sufficiently humid regimen reappeared, it was the peat 

 which ujidertook to fill up the main water-courses, wherever the 

 permeability of the slopes secured for the rivers a regimen exempt 

 from violent floods. With the bogs commences the actually existing 

 regimen. During the period of dry cold, the faujia of the Mammals 

 was that of the Siberian steppes. The humidity of the age of the 

 bogs by favouring the development of timber, determined the 

 inco min g of a forest fauna. The temperature henceforward under- 

 goes but slight vicissitudes, and with the exception of some alterna- 

 tions of invasion and retreat of the sea in the Flemish regions, the 

 contours of the continents have become fixed, and the story of 

 succeeding events belongs rather to Ai'chseology and to History than 

 to Geology." 



At p. 247 of his work already cited Boyd Dawkins says : " The 



