328 REPORTS OP RESEARCH COMMITTEES. 



(c) Wind Action generally. — Jutson (14, 15, 18, 19, 20, 

 25, 27), Maitland (30), and Woodward (93) believe the wind 

 to be an important agent affecting the surface configuration. 

 Montgomery |^31) regards it as of little^ importance. Honman 

 (7, 8, 9^ 11) and Blatchford (2) attach some importance to the 

 wind. Talbot and Clarke (36, 37), restricting their remarks 

 to the area examined by them, regard the wind as acting 

 slowly as a transporting agent, and practically negligibly as 

 a corrading agent. 



(d) " 7ireali((ivai/s," which may be defined as lines of 

 usually laterite-capped cliffs connecting two plateaux. The 

 mode of foimation of breakaways has been discussed by 

 Woodward (39), Honman (7), Montgomery (31), Jutson 

 (13, 14, 15), and Talbot and Clarke (36, 37). Jutson (15) 

 recognises a primary and a secondary system of breakaways, 

 and Plonman (7, 10) several levels O'f breakaways. 



(c) Sand Rid</es, Sand Flaiiis, and " Sand Glaciers." — 

 flonman (7, 8, 9, 11) holds that the sand plains are in part 

 due to wind action, and he, and also Jutson (19), note the 

 occurrence of sand ridges and plains on the eastern shores 

 of the lakes, with rock floors on the western. Jutson (20) 

 instances a sand plain, as well as sand ridges and '' sand 

 glaciers," as due to wind action, and (18) discusses the rela- 

 tion of a specific area of sand ridges to a "dry" lake. 

 Montgcniery (31) regards many sand ridges as having sur- 

 rounded former great lakes, since dried up. 



(/) " Deep Leads."- — Montgomery (31) shows the occur- 

 rence of many leads, and believes that some may be connected 

 with the " dry " lakes. Jutson (14, 15, 28) has discussed the 

 various possible theories as to the origin of the leads. 



(//) Inffnenrc of Salts in Eoch Weathering. — Jutson (17) 

 describes the mechanical disintegration of rocks by the crys- 

 tallization of salts on the surfaces of rocks forming lake floors, 

 and forming the Icwer portions of lake cliffs, but suggests that 

 further research is required. 



{h) Origin of Salt in Underground Waters. — Montgomery 

 (31) holds that this salt is derived from a marine source, 

 rather than directly from integral constituents of the bed- 

 rock . 



(i) " Xiitii/a/ (Quarries." — Jiitson (16) shows that these 

 quarries are of three kinds — circular, rectangular, and tri- 

 angular ; and that they are chiefly due to the mechanical 

 gouging or undermining action of rain under certain special 

 conditions. 



