Canterbury and Westland. 191 



the gradual deeper washing out or excavation of the valleys. I have 

 already remarked that most of the principal valleys contract before 

 they enter the Canterbury plains from the lower Alps, but some of 

 those which, in the Ice period, lodged particularly large masses of 

 glaciers, form an exception to this rule. I will only quote one as an 

 example : the Bakaia valley, which continues to widen without 

 interruption until it enters the Canterbury plains, where it has attained 

 a breadth of five miles. This is, however, quite natural when we find 

 the last terminal moraine on the Canterbury plains themselves, where 

 it extends oyer them in a half circle for ten miles, and shows clearly 

 that the ice masses of this glacier were so enormous, that when they 

 came out into the open plains they were able to extend into the form 

 of a gigantic fan. It is, therefore, a matter of course that along the 

 whole valley, from the sources of the glacier to the plains, not only 

 the mountain sides exhibit signs of glacier action and are fringed by 

 moraines of great extent, but that also the mountains in the valley itself 

 must possess the roche moutonnee form. Indeed the shape of those in 

 the neighbourhood of Lake Coleridge, a true glacier basin, is so peculiar 

 that they have been named " sugarloaves," and the colonists mistook 

 them to be volcanic cones, until I was able to make them acquainted 

 with the real cause of their peculiar form. Thus the Southern Island 

 of New Zealand owes it principally to the Ice Period that, united to the 

 North Island, it can lay claim to the title of " Britain of the South," 

 because by its operations have been formed the magnificent plains for 

 agriculture, and the rounded hills and mountain sides so favourable for 

 depasturing cattle and sheep. I have taken the liberty of making this 

 digression, in order to explain the peculiar conditions which surround 

 the traveller the farther he penetrates into the heart of the Alps, and 

 which would remain a mystery to him had not geological researches 

 supplied the key to their explanation. 



The divergent ranges between the Takapo and Pukaki systems, 

 although very high, are not extensive as they terminate at the northern 

 boundary of the Mackenzie plains. The rivers Cass and Jollie have 

 their glacier sources amongst them. Whilst this latter range consists 

 of three parallel chains, the high mountain range which begins east of 

 the rocky saddle between the Moorhouse and Sealy ranges, has only 

 one water-shed, the eastern side draining into the Tasman and the 

 western into the Dobson river. It is nearly forty miles long, and 

 many peaks of its northern portion are covered with perpetual snow. 

 As the Ben Ohau range, where it has lost considerably in its altitude, 

 it slopes to the Mackenzie plains, near the outlet of Lake Ohau. 



