viction, not only of the importance of
the subject, but of the soundness of the conclusions he has reached,
and of the necessity of bringing physiological facts and laws
prominently to the notice of all who are interested in education,
conspires with the interest excited by the theme of his lecture to
justify him in presenting these pages to the public. The leisure of
his last professional vacation has been devoted to their preparation.
The original address, with the exception of a few verbal alterations,
is incorporated into them.

Great plainness of speech will be observed throughout this essay. The
nature of the subject it discusses, the general misapprehension both
of the strong and weak points in the physiology of the woman question,
and the ignorance displayed by many, of what the co-education of the
sexes really means, all forbid that ambiguity of language or euphemism
of expression should be employed in the discussion. The subject is
treated solely from the standpoint of physiology. Technical terms
have been employed, only where their use is more exact or less
offensive than common ones.

If the publication of this brief memoir does nothing more than excite
discussion and stimulate investigation with regard to a matter of such
vital moment to the nation as the relation of sex to education, the
author will be amply repaid for the time and labor of its preparation.
No one can appreciate more than he its imperfections. Notwithstanding
these, he hopes a little good may be extracted from it, and so
commends it to the consideration of all who desire the _best_
education of the sexes.

BOSTON, 18 ARLINGTON STREET, October, 1873.

PREFACE TO SECOND EDITION.

The demand for a second edition of this book in little more than a
week after the publication of the first, indicates the interest which
the public take in the relation of Sex to Education, and justifies the
author in appealing to physiology and pathology for light upon the
vexed question of the appropriate education of girls. Excepting a few
verbal alterations, and the correction of a few typographical errors,
there is no difference between this edition and the first. The author
would have been glad to add to this edition a section upon the
relation of sex to women's work in life, after their technical
education is completed, but has not had time to do so.

BOSTON, 18 ARLINGTON STREET,
Nov. 8, 1873.

NOTE TO THE FIFTH EDITION.