118 THE AUSTRALIAN NATURALIST. 
are three levels of fern-covered caves beneath our feet, but on 
passing a small waterfall (easily detected by the roar of the 
water) we find only two cave terraces, and so eventually after 
two more falls the track is again at stream level and we are 
walking through a fern-clad cave. 
The next feature of interest may easily be passed without 
being recognised, but even if this happens an observer has a 
second opportunity after ascending Neate’s Glen to the level 
at which ferns cease. He must then leave the track and climb 
back towards the Canyon. From the edge of a fine cliff a wider 
view presents itself, and it will be obvious that the river has 
changed its course at some fairly remote epoch; for a strongly 
marked line of clifis, fretted by deep caves, maintains a direc- 
tion in conformity with the main line of the Canyon, whereas 
the river sweeps round in a big curve convex towards Neate’s 
Glen. The river is again cutting a bow-shaped canyon, but 
the new wall is only about 100ft. in height. At this place the 
valley greatly exceeds its average breadth, for the space between 
the old cliff line and the new shallow canyon has been denuded 
down to the level of a hard bed of rock forming a flat-topped 
bluff or “bench” in the middle of the Canyon. ‘[his scene con- 
veys the best possible proof that the cutting of the gorge is due 
to water action alone, without any assistance from faults. The 
same scene affords an excellent set of examples showing the 
efficiency of the protection afforded against weathering by a 
hard stratum of rock. with massive jointing. This highly re- 
sisting rock overhangs the softer rocks below by many feet, and 
serves the same function as the eaves of a house. As the over- 
hang is considerable on both sides of the valley, the gully is 
much narrower at the top than at the bottom. In the same 
neighbourhood are some striking debris. When the river has 
succeeded in undercutting the cliffs nearly to the next joint 
plane, the whole cliff face falls, and renews its freshness and its 
vertical nature, but the valley is partly choked with debris. 
Again the massively jointed rock shows its superior durability, 
and several blocks of giant dimensions litter the valley, although 
the smaller pieces have long since been removed by the stream. 
Halfway between Neate’s Glen and Wall’s Cave we have 
another striking proof that the Canyon was not developed along 
a fault line. As we walk upstream the direction of the river 
makes a sudden turn of 180°, and the canyon structure suddenly 
ceases at the bend, where three striking bluffs look down the 
