The Book of Flies, inset at the beginning of this volume, is designed for the convenience of the many anglers who, amid the pressure of practical affairs, naturally find it difficult to remember the relations of the lures to the months of the season. In arranging the flies for streams I have had the invaluable assistance of Mr. William Senior, who revised, and in some cases added to, the lists which I had drawn up. What are known as "local flies," lures in imitation of insects found only on certain rivers, are not included. Still, it is believed that as regards the flies for running waters the lists are comprehensive. All possible care has been taken to ensure that the images are exactly life-size.

The selection and arrangement of the lake flies has been much more difficult. The few authorities to whom I submitted my own distributions were sceptical as to the possibility of stating exactly what lake flies were appropriate to any particular month. For example, Mr. Robert Anderson, Edinburgh, who has been fishing, and supplying flies to other fishermen, for over forty years, thought that they could be separated only into those which might be called "summer flies" and those which could be used all through the season. This opinion commanded respect; yet there were strong reasons for believing that the very inexact state of the science of lake-fishing was no more than a reflection of the strangely casual manner in which angling is practised on the lakes. These reasons were derived from observation and experience. The insects that flutter about the lakes appear just as regularly, in their seasons, as the insects which haunt the streams; and they are no less distinct in their varieties. It was natural to assume, therefore, that the flies which would be fitting lures at one time would not be fitting at others; and that for the other times there were appropriate flies, if only one could find them. The arrangement set forth in The Booh of Flies is the result of observations and experiments which have at least been constant and painstaking.

The problem of the lake flies, however, was not completely solved when the distribution into months had been settled. In what sizes were the lures to be presented ? Naturalists admit that the standard sizes are as a rule larger than the real insects; yet, in spite of this, practically all anglers use flies of the standard patterns. This habit is not in accord with the assumption set forth in the pages that are to follow, which is that Nature is the true guide. Nevertheless, excepting in the cases of the Green Drake and the Stonefly, which are life-size, the standards are adopted in The Book of Flies. After much consideration, there were three reasons for this course. In the first place, however strong might be one's own opinion on the subject of lake flies, which has not until now, I believe, been treated systematically, it seemed right to defer to general usage to the extent, at least, of stating what the usage was. In the second place, experience renders it impossible to deny that sometimes the standard sizes are to be considered right, or, at any rate, not wrong. When the wind is high, all the aspects of a lake, even its length and breadth, seem to be on a larger scale, and to grow with the growth of the waves; the very trout increase in voracity and in daring then, and come at the standard flies so well that it is not easy to consider the standards a mistake. In the third place, many of the lakes which contain brown trout contain, at times, sea-trout and salmon also; and in regard to these fish flies larger than the real insects are certainly an advantage. It has been found that salmon now and then, and sea-trout very often, take the lures of which the images are here presented. At the same time, while adopting the standard sizes of the lake flies for these reasons and in deference to usage, I cannot candidly conceal the belief, which is more than theoretical, that even in a high wind lures of smaller size succeed, with the brown trout, just as well; nor ought I to conceal the absolute certainty that in a light wind, or in a calm, lures of the smaller size will be found much better. Indeed, when the wind is light, not only lake flies smaller than the standard, but also some of the stream flies, are often exceedingly successful.

Some may be surprised to see Wasps figuring among the lake flies. Wasps, it may be said, are not water insects. That is true; but neither is the Alder, a favourite on rivers, a water insect in the sense that a Stonefly is. Still, just as the trout in a stream take Alders that are blown on the water by high wind, Wasps sometimes fall upon the lake, and the fish rise at them.

It should, of course, be understood that the lists in The Book of Flies are not to be considered absolutely rigid. As regards weather one month glides into another imperceptibly, and it is not to be supposed that when any month is over all the flies shown under its heading are obsolete for the season. For example, in The Book of Flies the Mayfly appears under the heading "June," because as a rule Nature sends it forth in that month, early; but now and then, in the South of England, if the weather is propitious it appears on the streams towards the close of the month after which it is named. Similarly, most of the other insects, like the cereals of the fields, are often a week or two weeks early, or late, according to the weather. The lists in The Book of Flies, then, are to be considered as stating the ascertained averages, not as a code of inflexible time-tables.

Although, if I be not mistaken, The Book of Flies now presented is the first of its kind, pictures of flies, arranged for other purposes, are not uncommon; but much difficulty, I am informed, has been found in the attempts to reproduce the colours exactly. "I warn you," said Mr. Senior, in a letter about my own plan, "that you are likely to have immense trouble over the coloured illustrations; for I have known Halford, Marston, and everybody who has gone through the ordeal, driven frantic in their efforts to get the colours right." Within recent months, happily, there has been much progress in the methods of reproducing coloured pictures; and I am confident that the effort in this volume will be found successful. Through the influence of the publishers, Messrs. A. and C. Black, who have taken a kindly and very gratifying interest in this book, sparing no expense of trouble or of money in its production, I have had high good fortune in the difficulty to which Mr. Senior refers. The artist of The Book of Flies is Mr. Mortimer Menpes. Luck did not end there. On the publishers suggesting that a frontispiece would be acceptable, I remembered a captivating picture, by Rolfe, hanging over the fireplace in the hall of a mirthful shooting-lodge in Kent. Leave to have that picture reproduced in " Trout Fishing" was given by the owner, Mr. T. J. Barratt, willingly. Indeed, the friendliness of all who have helped me in this book is so enthusiastic that now I have a very real apprehension lest the essay itself should fall short of their expectations. Among these friends I include Messrs. Hardy, Alnwick, who made for me the models of the stream flies, and Mr. Robert Anderson, who made those of the lake flies.

It may be that readers of the little book will now and then seem to catch an echo of something they have heard or read before. If so, that will be because, in the later days of Mr. Richard Holt Hutton, I had the honour to write a good many articles on Angling in " The Spectator," and, afterwards, others in " The National Review," " The Saturday Review," " The Speaker" " The Academy" " The Daily Chronicle" " The Morning Post" and " The Pall Mall Gazette" It is possible that there may be an echo, or what seems to be one; but that will be merely incidental. This writing as a whole is new. The closing chapter appeared in the " Cornhill Magazine" and part of " The Wind" in "The Daily Mail"; but these were written as integral portions of the book, which, whatever its defects, is the result of an orderly plan.