F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

fertile females, and yet, from being sterile, they cannot propagate their kind. The subject well deserves to be discussed at great length, but I will here take only a single case, that of working or sterile ants. How the workers have been rendered sterile is a difficulty; but not much greater than that of any other striking modification of structure; for it can be shown that some insects and other articulate animals in a state of nature occasionally become sterile; and if such insects had been social

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

labour is useful to civilised man. As ants work by inherited instincts and by inherited tools or weapons, and not by acquired knowledge and manufactured instruments, a perfect division of labour could be effected with them only by the workers being sterile; for had they been fertile, they would have intercrossed, and their instincts and structure would have become blended. And nature has, as I believe, effected this admirable division of labour in the communities of ants, by the means of

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

materials for the nest: both, but chiefly the slaves, tend, and milk as it may be called, their aphides; and thus both collect food for the community. In England the masters alone usually leave the nest to collect building materials and food for themselves, their slaves and larvæ. So that the masters in this country receive much less service from their slaves than they do in Switzerland. By what steps the instinct of F. sanguinea originated I will not pretend to conjecture. But as ants, which are

CUL-DAR185.109.22    Draft:    [1859]   Draft of Origin, fair copy folio 23, Chap VII Instinct. / Drawing: Birds and Butterfly: Childrens' drawings on verso   Text   Image

The Complete Work of Charles Darwin Online [23] 23 Chap. VII Instinct. Slave-making instinct.— We will now turn to the extraordinary slave-making instinct of certain Ants. The Formica (Polyerges) rufescens, as was first discovered by Pierre Huber, a better observer even than his celebrated father, is absolutely dependent on its slaves. Without their aid the species in a single year would certainly become extinct. The males and females do no work: and the workers or sterile females, though most

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

instinct of certain ants; and the comb-making power of the hive-bee: these two latter instincts have generally, and most justly, been ranked by naturalists as the most wonderful of all known instincts. It is now commonly admitted that the more immediate and final cause of the cuckoo's instinct is, that [page] 217 CHAP. VII. OF THE CUCKOO

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

of difference between the fertile and sterile females of the same species has been produced, which we see in many social insects. But we have not as yet touched on the climax of the difficulty; namely, the fact that the neuters of several ants differ, not only from the fertile females and males, but from each other, sometimes to an almost incredible degree, and are thus divided into two or even three castes. The castes, moreover, do not generally graduate into each other, but are perfectly well

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

a house of whom many were five feet four inches high, and many sixteen feet high; but we must suppose that the larger workmen had heads four instead of three times as big as those of the smaller men, and jaws nearly five times as big. The jaws, moreover, of the working ants of the several sizes differed wonderfully in shape, and in the form and number of the teeth. But the important fact for us is, that though the workers can be grouped into castes of different sizes, yet they graduate

F373    Book:     Darwin, C. R. 1859. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 1st ed., 1st issue.   Text   Image   PDF

. Horner, Mr., on the antiquity of Egyptians, 18. Horns, rudimentary, 454. Horse, fossil, in La Plata, 318. Horses destroyed by flies in La Plata, 72. ——, striped, 163. ——, proportions of, when young, 445. Horticulturists, selection applied by, 32. Huber on cells of bees, 230. ——, P., on reason blended with instinct, 208. ——, on habitual nature of instincts, 208. ——, on slave making ants, 219. ——, on Melipona domestica, 225. Humble-bees, cells of, 225. Hunter, J., on secondary sexual characters, 150

CUL-DAR205.11.96-97    Note:    1859.07.23--1859.07.25   Observed numbers of ants by great nest by Wall F[ormica] rufa or wood-ant   Text   Image

skins. Another, I believe dropped it several yards further off. The skins retard progress of ant greatly; the larger torn skins most, so that then are dropped by others carrying skins— Labor useless for they are so light that gentlest breeze blows them away.— I took two skins from 2 ants on the road brought them to near nest, then soon 2 ants started with them on the same journey. The preciousness of pupæ perhaps helps blunder. Begin with Birds broken egg-shells.— admit no doubt useful from vast

CUL-DAR226.1.50    Printed:    1859.12.03   [Crawfurd, J.] 1859. [Review of Origin]. Examiner (3 December), pp. 772-73.   Text   Image   PDF

and some preparation for the task. All, however, is by no means of this description, and many parts of the work abound in information, easy to comprehend and both instructive and entertaining. Mr Darwin's account of the slave-making ants, for there are several species of them, is an example. It will be observed that, as with human slave-dealing, the slave is black, and the dealer, if not white, at least red or fairer. The eloquent concluding paragraph of the work is another among the many which