to the body and mind. I also attributed some amount of modification to the direct and prolonged action of changed conditions of life. Some allowance, too, must be made for Occasional reversions of structure; nor must we forget what I have called "correlated" growth, meaning thereby, that various parts of the organization are in some unknown manner so connected, that when one part varies, so do others; and if variations in the one are accumulated by selection, other parts will be modified. Again, it has been said by several critics, that when I found that many details of structure in man could not be explained through natural selection, I invented sexual selection; I gave, however, a tolerably clear sketch of this principle in the first edition of the "Origin of Species," and I there stated that it was applicable to man. This subject of sexual selection has been treated at full length in the present work, simply because an opportunity was here first afforded me. I have been struck with the likeness of many of the half-favorable criticisms on sexual selection with those which appeared at first on natural selection; such as, that it would explain some few details, but certainly was not applicable to the extent to which I have employed it. My conviction of the power of sexual selection remains unshaken; but it is probable, or almost certain, that several of my conclusions will hereafter be found erroneous; this can hardly fail to be the case in the first treatment of a subject. When naturalists have become familiar with the idea of sexual selection, it will, as I believe, be much more largely accepted; and it has already been fully and favorably received by several capable judges.

DOWN, BECKEnham, Kent,
September, 1874

TABLE

OF THE

PRINCIPAL ADDITIONS AND CORRECTIONS TO

THE PRESENT EDITION

First Edition

VOL. I.

Page

22

Present Edition

Vol. I.

Page 33-35

38

39, note.

42-43 44, note.

101

42

102

Discussion on the rudimentary points in the human ear revised.

Cases of men born with hairy bodies.

Mantegazza on the last molar
tooth in man.

The rudiments of a tail in man.
Bianconi on homologous struct-
ures, as explained by adapta
tion on mechanical principles.
Intelligence in a baboon.
Sense of humor in dogs.

Further facts on imitation in man
and animals.

Reasoning power in the lower animals.

Acquisition of experience by animals.

Power of abstraction in animals. Power of forming concepts in relation to language.

Pleasure from certain sounds,
colors, and forms.

Fidelity in the elephant.
Galton on gregariousness of
cattle.

Parental affection.

Persistence of enmity and hatred.

Greater variability of male than female; direct action of the environment in causing differences between the sexes. Period of development of protuberances on birds' heads determines their transmission to one or both sexes.

Causes of excess of male births. Proportion of the sexes in the bee family.

Excess of males perhaps sometimes determined by selection. Bright colors of lowly organized animals.

Sexual selection among spiders. Cause of smallness of male spiders.

Use of phosphorescence of the
glow-worm.

The humming noises of flies.
Use of bright colors to Hemip-
tera (bugs).

Musical apparatus of Homoptera.
Development of stridulating ap
paratus in Orthoptera.

Herman Müller on sexual differ. ences of bees.

Sounds produced by moths. Display of beauty by butterflies.

Female butterflies, taking the more active part in courtship, brighter than their males. Further cases of mimicry in but. terflies and moths.

Cause of bright and diversified colors of caterpillars.

Brushlike scales of male Mallotus.