It is indeed, of course, almost the first thing to be asked that boys and girls shall learn to find out for themselves what they want, and to rummage in catalogues, indexes, and encyclopædias for the books which will best answer their necessities. Mr. Emerson's rule is, "Read in the line of your genius." And the young man or maiden who can find out, in early life, what the line of his or her genius is, has every reason to be grateful to the teacher, or the event, or the book that has discovered it. I have certainly hoped, in reading and writing for this series, that there might be others of my young friends as sensible and as bright as Fergus and Fanchon, who will be found to work out their own salvation in these matters, and order their own books without troubling too much that nice Miss Panizzi or that omniscient Mrs. Bodley who manages the Library so well, and knows so well what every one in the town has read, and what he has not read. I had at first proposed to publish with each book a little bibliography on the subjects referred to, telling particularly where were the available editions and the prices at which they could be bought by young collectors. But a little experiment showed that no such supplement could be made, which should be of real use for most readers for whom these books are made. The same list might be too full for those who have only small libraries at command, and too brief for those who are fortunate enough to use large ones. Indeed, I should like to say to such young readers of mine as have the pluck and the sense to read a preface, that the sooner they find out how to use the received guides in such matters,--the very indexes and bibliographies which I should use in making such a list for them,--why, the better will it be for them. Such books as Poole's Index, Watt's and Brunet's Bibliographies, and the New American Indexes, prepared with such care by the Librarians' Association, are at hand in almost all the Public Libraries; and the librarians will always be glad to encourage intelligent readers in the use of them. I should be sorry, in closing the series, not to bear my testimony to the value of the Public Library system, still so new to us, in raising the standard of thought and education. For thirty years I have had more or less to do with classes of intelligent young people who have met for study. I can say, therefore, that the habit of thought and the habit of work of such young people now is different from what it was thirty years ago. Of course it ought to be. You can say to a young learner now, "This book says thus and so, but you must learn for yourself whether this author is prejudiced or ill-informed, or not."