. THE VICTORIAN NATURALIST. 103 



show a marked contrast to the plain to the south-west. Here the 

 valleys are much deeper and narrower, as is well known to those 

 who are familiar with the Mullum Mullum and Anderson Creeks. 

 A good survey of much of the area is obtained from some of the 

 hills near Mitcham. From this neighbourhood several valleys 

 diverge, notably those of the Mullum Mullum, the Koonung, the 

 Main, and the Dandenong Creeks. 



Looking southwards from Mitcham, the fairly even surface of 

 the plain is seen to end rather abruptly along a southerly line 

 extending south towards Clayton, on the Gippsland railway. A 

 fairly broad valley of the Dandenong Creek drains south between 

 this line and the Dandenong Range. This depression adds con- 

 siderably to the rather imposing view of the ranges obtained from 

 Mitcham. The district south from Box Hill to the Gippsland 

 line, across the upper part of the Gardiner's Creek basin, shows 

 clearly the character of an intermediate stage between the simple 

 southern plain and the relatively mature dissection of the undu- 

 lating slope northward to the Yarra. 



When one, standing on one of the vantage points, reconstructs 

 mentally this partially destroyed plain, the enormous amount of 

 rock material carried away by running water in comparatively recent 

 times is strikingly brought home. One of the results of the 

 relatively greater erosive activity of the Yarra tributaries of this 

 area over the other streams is that the drainage area of the former 

 has been gradually increased by the southerly shift of the water- 

 shed as the head waters of the first-named valleys have eaten their 

 way back. 



Probably one of the most recent events in this direction is 

 shown in the upper course of the Mullum Mullum or Deep 

 Creek. The divide which originally separated the waters of this 

 valley from the Dandenong Creek basin is still well defined. It 

 runs north-east from Mitcham more or less parallel with the Lily- 

 dale railway line, and lies about half a mile to a mile north of it 

 at Ringwood, where a conspicuous conical hill, known as Pine- 

 mont, rises to about 600 feet above sea level, and marks clearly 

 the position of the old water parting. 



The intervening valley heads up to the north-east in the direc- 

 tion of Burt's Hill. It is a comparatively fiat-bottomed valley, 

 which clearly belonged at no very remote date to the Dandenong 

 Creek basin, and into which it drained through a well-defined 

 depression to the west of the Ringwood station. 



Between Pinemont and Mitcham, but closer to the former 

 position, a comparatively narrow, deep gorge has been cut by the 

 original head waters of the Mullum Mullum, from the north side. 

 The breach thus made tapped the valley on the southern side, 

 and thereby captured its waters. This event has been marked by 

 a certain amount of renewed corrosive activity on the part of this 



