Speight. — Physiography of the Cass District. 153 



and partly with tussock. As a geologist, I should like to knOw which 

 plant fornaation was first established on these fans — forest or tussock grass- 

 land. The Cass River bed is an active fan on a gentle grade, accommo- 

 dating itself to the volume of the stream and the supply of waste, both 

 bemg relatively large. In the valley towards Lake Pearson there are many 

 active and decadent fans, especially on the lower slopes of the Craigieburn 

 Range and Mount St. Bernard. They have spread over the floor of the 

 valley from various points in the sides, dividing it into sections, interfering 

 with the drainage, and thus forming, or helping to form, lakes, such as 

 Grasraere and Sarah, and again filling them up by the lateral extension 

 of the margins of the fan. They are perhaps as important factors in stream- 

 diversion as glaciers, and are the most distinctive agents in the production 

 of landscape features since the ice retreated. I can only suggest, in con- 

 clusion, that the position of the biological station affords an admirable 

 opportunity for a detailed study of their true mathematical form and other 

 characters, and a careful investigation into these would furnish results 

 which would be quite worth the time and trouble spent in obtaining them. 



Bibliography. 



The following publications may be consulted as regards special aspects 

 of the physiography of the locality : — 



1865. Dobson, Edward. " The Possibility of constructing a Road through 

 the Otira Gorge." Report furnished to the Canterbury Provincial 

 Council. 



1879. Haast, Julius von. " Geology of the Provinces of Canterbury and 

 Westland." Christchurch. 



1907. Speight, R. " Notes on some of the New Zealand Glaciers in the 

 District of Canterbury." Report of Aust. Ass. Adv. Sci., 1907, p. 285. 



1909. Gudex, M. C. " Some Striated Stones from the St. Bernard Saddle, 

 Upper Waimakariri Valley." Trans. N.Z. Inst., vol. 41, p. 33. 



1915. Speight, R. "The Intermontane Basins of Canterbmy." Trans. 

 N.Z. Inst., vol. 47, p. 336. 



1916. Speight, R. " The Orientation of the River- Valleys of Canterbury." 

 Trans. N.Z. Inst., vol. 48, p. 137. 



