426 



AUSTEAI.ASIA. 



On the west side the glaciers, being fed by more abundant snows, descend much 

 lower, that of Cook approaching to within 790 feet of the sea-level. But here the 

 valleys are too short to allow the congealed rivers the same development as on the 

 east slope. On both sides, however, all the glaciers were formerly far more 

 extensive than at present, as shown by the still existing moraines, polished rocks, 



Fig. 183. — Tasman Glacier. 

 Scale 1 : 800,000. 









45' 



^ F L- 



. 18 Miles. 



and lakes. According to Green the New Zealand glaciers have again entered on a 

 period of expansion. 



While the highlands are still in the glacial epoch, the plains, and especially 

 those of South Island, have reached the lacustrine phase. The beds of the former 

 frozen streams are now partly filled by lakes, which are dammed up at their lower 

 end by old frontal moraines, and which higher up are gradually being filled up 



