es, gain a
darker hue. I do not, however, mean to say that they are the same flies,
but more probably successive generations of ephemerae of the same
species. The excess of heat seems equally unfavourable, as the excess of
cold, to the existence of the smaller species of water-insects, which,
during the intensity of sunshine, seldom appear in summer, but rise
morning and evening only. The blue dun has, in June and July, a yellow
body; and there is a water-fly which, in the evening, is generally found
before the moths appear, called the red spinner. Towards the end of
August, the ephemerae appear again in the middle of the day--a very
pale, small ephemera, which is of the same colour as that which is seen
in some rivers in the beginning of July. In September and October this
kind of fly is found with an olive body, and it becomes darker in
October and paler in November. There are two other flies which appear in
the end of September and continue during October, if the weather be
mild; a large yellow fly, with a fleshy body, and wings like a moth; and
a small fly with four wings, with a dark or claret coloured body, that
when it falls on the water has its wings like the great yellow fly, flat
on its back. This, or a claret bodied fly, very similar in character,
may be likewise found in March or April, on some waters. In this river I
have often caught many large trout in April and the beginning of May,
with the blue dun, having the yellow body; and in the upper part of the
stream below St. Albans, and between that and Watford, I have sometimes,
even as early as April, caught fish in good condition; but the _true_
season for the Colne is the season of the May-fly. The same may be said
of most of the large English rivers containing large trouts, and
abounding in May-fly--such as the Test and the Kennett, the one running
by Stockbridge, the other by Hungerford. But in the Wandle, at
Carshalton and Beddington, the May-fly is not found; and the little
blues are the constant, and, when well imitated, killing flies on this
water; to which may be joined a dark alder-fly, and a red evening fly.
In the Avon, at Ringwood and Fordingbridge, the May-fly is likewise a
killing fly; but as this is a grayling river, the other flies,
particularly the grannam and blue and brown, are good in spring, and the
alder-fly or pale blue later, and the blue dun in September and October,
and even November. In the streams in the mountainous parts of Brita