10 XXXII. Dr. J. V. Daaeš: 



Mr. Taylor, however, points out two facts, which cannot be de- 

 nied: 1. the prevailing north-south direction of the drainage 2. the 

 late development of the présent inouths, due to a subsidence along 

 the coast. 



The puzzle of the Darling River tributaries on the Darling Do- 

 wns, especially the stränge course of the Condamine seems to me to 

 find a more natural solution in the following way : There was an in- 

 land basin on the middle Condamine in the neighbourhood of Dalby 

 which only lately has been captured by the tributary of the Darling 

 River. The „obsequent" little streams (Mr. Taylor on page 11.) which 

 flow into the Condamine from the Darky Fiat can be rather betrunked 

 rivers, which háve been beheaded by the more vigorous Moonie and 

 Macintyre. 



III. 



Referring to Mr. Hedley's paper x ) I shall dwell longer on those 

 Problems only which have not been accepted unanimously and shall 

 tvy to explain my views, which are in some points diverging from 

 those of Mr. Hedley's. As a substrate for the foliowing considérations 

 I may quote some rather longer passages from his study : 



„Previous to the présent cycle, that of. Mr. Kosciusko, it is be- 

 lieved by geologists that a great peneplain extended from New Gui- 

 nea, in the north, to Tasmania, in the south. Probably this peneplain 

 extended eastwards beyond the limit of the présent coast and was 

 continued seawards by a broad continental shelf. Probably also the 

 ocean eastwards was then shallower and narrower than today." 



„The theory is now advanced that the présent cycle commenced 

 by the sinkink of the ocean-floor, aud by pressure upon the border 

 of the continent. In the zone of compression, folding on a large scale 

 ensued, by which the continental shelf was depressed, and the coa- 

 stal range elevated, simultaneously". 



[This point is opposed strongly by Mr. Andrews, who holds that the 

 pressure came from the south, working through the land against the 

 pacifie coast and not from the sea to the land.] 



„In support, it is demonstrated that harmony exists between the 

 margin of the continental shelf on the one side, and the line of the 

 Pacific watershed on the other. Where the margin of the shelf ap- 



') A Study of Marginal Drainage. Presidential Adre3s. By C. Hedley 

 F. L. S. Vol. XXXVI. Part. 1., March. Proceedings of the Linnean Society of New 

 South. Wales 1911. (Issued 17th. August, 1911. 



