THE OLD RED SANDSTONE. 209 
it is probable that the denuded members of the Cretaceous 
group once rested upon it there. The fact that a deposit 
should be found lying in contact with the gneiss, furnishes no 
argument for the great antiquity or the fundamental charac- 
ter of that deposit; and it were well that the geologist who 
sets himself to estimate the depth of the Old Red Sandstone, 
or the succession of its various formations, should keep the 
circumstance in view. That may be in reality but a small 
and upper portion of the system which he finds bounded by 
the gneiss on its under side, and by the diluvium on its upper. 
We stand on a wooded eminence, that sinks perpendicu- 
larly into the river on the left, in a mural precipice, and de- 
scends with a billowy swell into the broad, fertile plain in 
front, as if the uplands were breaking in one vast wave upon 
the low country. There is a patch of meadow on the oppo- 
site side of the stream, shaded by a group of ancient trees, 
gnarled and mossy, and with half their topmost branches 
dead and white as the bones of a skeleton. We look down 
upon them from an elevation so commanding, that their up- 
permost twigs seem on well nigh the same level with their 
interlaced and twisted roots, washed bare on the bank edge 
by the winter floods. A colony of herons has built from time 
immemorial among the branches. There are trees so laden 
with nests that the boughs bend earthwards on every side, 
like the boughs of orchard trees in autumn; and the bleached 
and feathered masses which they bear —the cradles of suc- 
ceeding generations — glitter gray through the foliage in con- 
tinuous groups, as if each tree bore on its single head all the 
wigs of the Court of Session. The solitude is busy with the 
occupations and enjoyments of instinct. The birds, tall and 
stately, stand by troops in the shallows, or wade warily, as 
the fish glance by, to the edge of the current, or rising, with 
