TRANSLATORS NOTE THE present volume contains all the essays on Flies, or Diptera, from the Souveniers etztomologiqrres, to which I have added, in order to make the dimensions uniform with those of the other volumes of the series, the purely autobiographical essays comprised in the Sorrvetrirs. These essays, though they have no bearing upon the life of the Fly, are among the most interesting that Henri Fabre has written and will, I am persuaded, make a special appeal to the reader. The chapter entitled The Caddis-worm has been included as following directly upon The Potzd. Since publishing The Life of the Spider, I was much struck by a passage in Dr. Chalmers Mitchells stimulating work, The Childhood of Animals, in which the secretary of the Zoological Society of London says I have attempted to avoid the use of terms familiar only to students of zoology and to refrain from anatomical detail, but at the same time to refrain from the irritating habit of The Life of the Fly of assuming that my readers have no knowledge, no dictionaries and no other books. I began to wonder whether I had gone too far in simplifying the terminology of the Fabre essays and in appending explanatory footnotes to the inevitable number of outlandish names of insects. But my doubts vanished when I thought upon Fabres own words in the first chapter of this book If I write for men of learning, for philosophers . . . I write above all things for the young. I want to make them love the natural history which you make them hate and that is why, while keeping strictly to the domain of truth, I avoid your scientific prose, which too often, alas, seems borrowed from some roquoisidiom And I can but apologize if I have been too lavish with my notes to this chapter in particular, which introduces to us, as in a sort of litany, a multitude of the insects studied by the author. For the rest, I have continued my system of references to the earlier Fabre boolts, whether translated by myself or others. Of the following essays, The Harmas has appeared, under another title, in The Daily Mail The Pond, Industrial Chemistry and the two chapters on the Bluebottle in The English Review and The Harlmns, The Pond and Industrial Chemistry in the New York Bookmaa. The others are new to England and America, unless any of them should be issued in newspapers or magazines between this date and the publication of the book. I wish once more to thank Miss Frances Rodwell for her assistance in the details of my work and in the verification of the many references and my thanks are also due to Mr. Edmard Cahen, who has been good enough to revise the two chemistry chapters for me, and to Mr. W. S. Graff Baker, who has performed the same kindly task towards the two chapters .............