The cordial reception given to this little book by the medical profession, by educators, and especially by the young men of the country, have by their demands for the book necessitated the appearance of new editions in such rapid succession that no far-reaching changes in the text have been possible even if they had been needed. Happily, no extensive changes have been required.
In the second edition several corrections, typographical and verbal, were made and additions made to the appendix. To the third edition the chapter on Development was added. The fourth and fifth editions received verbal changes here and added paragraphs there.
The sixth edition differs from the fifth in the addition of the author's portrait as a frontispiece, the addition of an answered question to the appendix and the listing of certain lecture topics, with press notices and letters.
The book seems to be meeting a demand for accurate information briefly and clearly stated.
THE AUTHOR.
Chicago, November 1, 1908.
FOREWORD.
Several years ago the author was asked by his students to present to them some of the facts of Sexual Physiology and Hygiene. The plea of "not a specialist in that line" was not accepted; so after a few weeks devoted to a careful study of the literature the subject was presented. It seemed to be acceptable, and other invitations followed in successive years not only from the author's own institution but from many others.
In the last few years the subject has been presented at all of the leading institutions of learning in the middle west—at some of them several times and always to large audiences.