flying Flome. 281 
are quite reversed—it is a sight to see from hence the 
long black stream in the air steadily flowing onwards 
to the wood below. They stretch from here to the 
roosting-trees, fully a mile and a half—literally as the 
crow flies; and backwards in the opposite direction 
the line reaches as far as the eye can see. It is safe 
to estimate that the aerial army’s line of march 
extends over quite five miles in one unbroken corps. 
The breadth they occupy in the atmosphere varies— 
now twenty yards, now fifty, now a hundred, on an 
average say fifty yards; but rooks do not fly very 
close together like starlings, and the mass, it may be 
observed, fly on the same plane. Instead of three or 
four layers one above the other, the greater number 
pass by at the same height from the ground, side by 
side on a level, as soldiers would march upon a road : 
not meaning, of course, an absolute, but a relative level. 
This formation is more apparent from an elevation— 
as it were, up among them—than from below; and 
looking along their line towards the distant wood it 
is like glancing under a black canopy. 
Small outlying parties straggle from the line— 
Now on one side, now on the other; sometimes a few 
descend to alight on trees in the meadows, where 
doubtless their nests were situated inthespring. For 
it is a habit of theirs, months after the nesting is over 
and also before it begins, to pay a flying visit to the 
trees in the evening, calling ex route to see that all is 
well and to assert possession. 
