130 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 7, 



collecting under it ? My theory, I think, will explain all possible 

 occurrences ; and I am certain, if applied to Switzerland or any 

 other (Alpine) country, it will be found that, generally, all similar 

 phenomena can be imderstood more easily by adopting it. You will 

 observe, on looking at the map, how very close the line in which 

 our Alpine lakes lie agrees with the general direction of the central 

 chain throughout the islands. 



" These lakes are indiscriminately in very hard rocks, as well as 

 in loose, schistose strata, and are either lying in accordance with the 

 strike or across it. In fact, every proof is offered that the geolo- 

 gical structure of the country has nothing whatever to do with 

 them. Only, the harder the rock, the shallower and shorter will 

 they be found to be. Also, rocks disintegrating into shingle will 

 sooner obliterate them than schistose rocks, which are more easily 

 destroyed by the erosion in the rivers, and the mud carried away to 

 the sea. Of course I have not the least intention to say that all 

 rocky basins are formed by glaciers, but only allude to our New 

 Zealand ones." 



Sir Eoderick Murchison then remarks that the views of Dr. Haast 

 diifer in most essential respects from those which he has advocated, 

 and that, whilst he has opposed, and still opposes, the theory of the 

 excavation of hard rocks so as to have formed deep basins in them, 

 the phenomena in New Zealand seem to be peculiar and well worthy 

 of due consideration, the more so as Dr. Haast, in his letter, well 

 describes those former geological changes of the surface which pre- 

 pared the lines of depression in which the glaciers descended, but 

 which he tells us they did not produce. 



3, Notes on the Causes which have led to the Excavation of deep 

 Lake-basins in Hakd Eocks in the Southern Alps of New 

 Zealand. By Julius Haast, Ph.D., F.L.S., F.G.S. 



[Communicated by Sir Roderick Mm-chison, K.C.B., F.E.S., F.G.S.] 

 (Abridged.) 

 The author first states his views respecting the changes which had 

 taken place in the physical features of New Zealand during the 

 later geological periods. He considers that, after the deposition of 

 the Pliocene strata of those islands, the country emerged, its chief 

 physical feature being a high mountain -range, but with depressions 

 which existed before the previous subsidence, though now partly 

 obliterated, and which in most cases ran either on the junction-line 

 of two formations or along faults, or else on the break of bold anti- 

 clinals. 



It is then observed that several causes had combined to pro- 

 duce a great accumulation of neves as soon as the higher portions of 

 the country had risen above the snow-line, especially the equa- 

 torial north-west and polar soiith-east winds coming, charged with 

 moisture, in directions at right angles to the principal mountain - 

 range of the islands, which runs from north-east to south-west. 



