In my last eight or nine long vacations I have occasionally found time to write a lecture for a Natural History Society, or a paper for Macmillan's Magazine. The present volume—I doubt if I can justly call it a book—consists of a selection of these lectures and papers. Most of them have been in print before, but where it seemed advisable I have altered and to some extent rewritten them. All were written in the leisure of summer days (counting September as a summer month), with the exception of the first, which I have prefixed as a kind of prologue to the rest. I should add that Chapter IV. was published last December in the form of a pamphlet by my friend Mr. Blackwell of Oxford.

Chapter X. has to do neither with birds nor books. But the subject of that little memoir was all