374 Geology of 



want of efficient drainage channels into account, that the line of 

 perpetual snow descended to a much lower position than it occupies at 

 present, even had the level of the land not been raised to a higher 

 elevation than it now occupies. The natural consequence of such 

 enormous accumulations of snow was the formation of glaciers of 

 gigantic proportions, descending in course of time by the pre-existing 

 or newly formed channels towards the sea, grinding down the rugosities 

 of bottom and sides. The action of the glaciers beginning to lay open 

 the rocks of the higher ranges soon offered sufficient material for 

 morainic accumulations, first on the glaciers themselves, and afterwards 

 at the terminal faces. The scooping action of the ice plough having 

 once begun to eat into the plateau-like ranges, not only in the main 

 course of the glaciers, but also in the lateral valleys, became more 

 extended every day, and furnished more and more material for the form- 

 ation of huge moraines. In their turn these moraines were destroyed 

 by the great torrents issuing from the glaciers, and ample material 

 was furnished for building up fan-like courses for the former. 

 Boulders, sand, and ooze raised considerably the sea bottom along both 

 coasts of this island, and the low land at the foot of the alpine ranges 

 was more or less enlarged according to the physical features obtaining. 

 It will thus be seen that without invoking the aid of cosmical causes, 

 which might or might not have existed, I attribute the great glaciation 

 of New Zealand to physical causes still now in operation, although on 

 a much smaller scale, and without even assuming that the country had 

 risen to a higher level than it occupies at present. 



As I shall show, when treating of the morainic accumulations along 

 the AVest Coast, it is clear that there at least the land could not have 

 stood at a higher level. We are forced to this conclusion when we 

 examine into the nature of the deposits occurring there. Of course I 

 need scarcely point out that the more plateau-like ranges at the 

 beginning of the Great Glacier period must have been considerably 

 higher than they are at present, without assuming a change of level 

 since then, because the destruction, brought about by the action of 

 the ice masses upon them, must have been enormous. To make my 

 view on the point clearer, I have added an ideal section No. 1 on plate 

 "No. 7, delineating the form of these plateau-like ranges, as they must 

 have appealed after their emergence from the sea at the time when 

 they stood nearly at the same level as we find them now. Taking 

 the enormous destruction since then into account, of which this 

 island at every step we take bears ample testimony, I think that, 



