Other cases of inherited mutilations.

First Edition, Volume II., Page 43.
Second Edition Volume II., Page 17.
An additional case of reversion due to a cross.

First Edition, Volume II., Page 72.
Second Edition Volume II., Page 48.
Inheritance as limited by sex.

First Edition, Volume II., Page 105.
Second Edition Volume II., Page 83.
Two varieties of maize which cannot be crossed.

First Edition, Volume II., Page 120.
Second Edition Volume II., Page 99.
Some additional facts on the advantages of cross-breeding in animals.

First Edition, Volume II., Page 123.
Second Edition Volume II., Page 103.
Discussion on the effects of close interbreeding in the case of man.

First Edition, Volume II., Page 135 to 141.
Second Edition Volume II., Page 117 to 122.
Additional cases of plants sterile with pollen from the same plant.

First Edition, Volume II., Page 149.
Second Edition Volume II., Page 131.
Mr. Sclater on the infertility of animals under confinement.

First Edition, Volume II., Page 152.
Second Edition Volume II., Page 134.
The Aperea a distinct species from the Guinea-pig.

First Edition, Volume II., Page 230.
Second Edition Volume II., Page 215.
Professor Jager on hawks killing light-coloured pigeons.

First Edition, Volume II., Page 273.
Second Edition Volume II., Page 262.
Professor Weismann on the effects of isolation in the development of
species.

First Edition, Volume II., Page 281.
Second Edition Volume II., Page 271.
The direct action of the conditions of life in causing variation.

First Edition, Volume II., Page 317.
Second Edition Volume II., Page 309.
Mr. Romanes on rudimentary parts.

First Edition, Volume II., Page 324 to 328.
Second Edition Volume II., Page 316 to 327.
Some additional cases of correlated variability.

First Edition, Volume II., Page 339.
Second Edition Volume II., Page 333.
On Geoffroy St.-Hilaire's law of "soi pour soi."

First Edition, Volume II., Page 357 to 404.
Second Edition Volume II., Page 349 to 399.
The chapter on Pangenesis has been largely altered and re-modelled; but the
essential principles remain the same.

THE VARIATION OF ANIMALS AND PLANTS UNDER DOMESTICATION.

INTRODUCTION.

The object of this work is not to describe all the many races of animals which have been domesticated by man, and of the plants which have been cultivated by him; even if I possessed the requisite knowledge, so gigantic an undertaking would be here superfluous. It is my intention to give under the head of each species only such facts as I have been able to collect or observe, showing the amount and nature of the changes which animals and plants have undergone whilst under man's dominion, or which bear on the general principles of variation. In one case alone, namely in that of the domestic pigeon, I will describe fully all the chief races, their history, the amount and nature of their differences, and the probable steps by which they have been formed. I have selected this case, because, as we shall hereafter see, the materials are better than in any other; and one case fully described will in fact illustrate all others. But I shall also describe domesticated rabbits, fowls, and ducks, with considerable fulness.

The subjects discussed in this volume are so connected that it is not a little difficult to decide how they can be best arranged. I have determined in the first part to give, under the heads of the various animals and plants, a large body of facts, some of which may at first appear but little related to our subject, and to devote the latter part to general discussions. Whenever I have found it necessary to give numerous details, in support of any proposition or conclusion, small type has been used. (Here shown with [].) The reader will, I think, find this plan a convenience, for, if he does not doubt the conclusion or care about the details, he can easily pass them over; yet I may be permitted to say that some of the discussions thus printed deserve attention, at least from the professed naturalist.

It may be useful to those who have read nothing about Natural Selection, if I here give a brief sketch of the whole subject and of its bearing on the origin of species. (Introduction/1. To any one who has attentively read my 'Origin of Species' this Introduction will be superfluous. As I stated in that work that I should soon publish the facts on which the conclusions given in it were founded, I here beg permission to remark that the great delay in publishing this first work has been caused by continued ill- health.) This is the more desirable, as it is impossible in the present work to avoid many allusions to questions which will be fully discussed in future volumes.

From a remote period, in all parts of the world, man has subjected many animals and plants to domestication or culture. Man has no power of altering the absolute conditions of life; he cannot change the climate of any country; he adds no new element to the soil; but he can remove an animal or plant from one climate or soil to another, and give it food on which it did not subsist in its natural state. It is an error to speak of man "tampering with nature" and causing variability. If a man drops a piece of iron into sulphuric acid, it cannot be said strictly that he makes the sulphate of iron, he only allows their elective affinities to come into play. If organic beings had not possessed an inherent tendency to vary, man could have done nothing. (Introduction/2. M. Pouchet has recently ('Plurality of Races' English Translation 1864 page 83 etc.) insisted that variation under domestication throws no light on the natural modification of species. I cannot perceive the force of his arguments, or, to speak more accurately, of his assertions to this effect.) He unintentionally exposes his animals and plants to various conditions of life, and variability supervenes, which he cannot even prevent or check. Consider the simple case of a plant which has been cultivated during a long time in its native country, and which consequently has not been subjected to any change of climate. It has been protected to a certain extent from the competing roots of plants of other kinds; it has generally been grown in manured soil; but probably not richer than that of many an alluvial flat; and lastly, it has been exposed to changes in its conditions, being grown sometimes in one district and sometimes in another, in different soils. Under such circumstances, scarcely a plant can be named, though cultivated in the rudest manner, which has not given birth to several varieties. It can hardly be maintained that during the many changes which this earth has undergone, and during the natural migrations of plants from one land or island to another, tenanted by different species, that such plants will not often have been subjected to changes in their conditions analogous to those which almost inevitably cause cultivated plants to vary. No doubt man selects varying individuals, sows their seeds, and again selects their varying offspring. But the initial variation on which man works, and without which he can do nothing, is caused by slight changes in the conditions of life, which must often have occurred under nature. Man, therefore, may be said to have been trying an experiment on a gigantic scale; and it is an experiment which nature during the long lapse of time has incessantly tried. Hence it follows that the principles of