PC-Virginia-Francis-F373    Printed:    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. [Francis Darwin's copy]  London   Text   Image   PDF

selection, 31. ——, two sub-breeds unintentionally produced, 36. ——, mountain, varieties of, 76. Shells, colours of, 132. ——, littoral, seldom embedded, 288. ——, fresh-water, dispersal of, 385. —— of Madeira, 391. ——, land, distribution of, 397. STRIPES. Silene, fertility of crosses, 257. Silliman, Prof., on blind rat, 137. Skulls of young mammals, 197, 437. Slave-making instinct, 219. Smith, Col. Hamilton, on striped horses, 164. ——, Mr. Fred., on slave-making ants, 219. ——, on neuter ants, 239

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

number of instincts have been acquired by habit in one generation, and then transmitted by inheritance to succeeding generations. It can be clearly shown that the most wonderful instincts with which we are acquainted, namely, those of the hive-bee and of many ants, could not possibly have been thus acquired. It will be universally admitted that instincts are as important as corporeal structure for the welfare of each species, under its present conditions of life. Under changed conditions of life, it

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

jaws. Another day my attention was struck by about a score of the slave-makers haunting the same spot, and evidently not in search of food; they approached and were vigorously repulsed by an independent community of the slave species (F. fusca); sometimes as many as three of these ants clinging to the legs of the slave-making F. sanguinea. The latter ruthlessly killed their small opponents, and carried their dead bodies as food to their nest, twenty-nine yards distant; but they were prevented from

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

the smaller workers, until all the workers had come to be in this condition; we should then have had a species of ant with neuters very nearly in the same condition with those of Myrmica. For the workers of Myrmica have not even rudiments of ocelli, though the male and female ants of this genus have well-developed ocelli. I may give one other case: so confidently did I expect to find gradations in important points of structure between the different castes of neuters in the same species, that I

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

special difficulty on the theory of natural selection; and one of the most curious of these is the existence of two or three defined castes of workers or sterile females in the same community of ants; but I have attempted to show how this difficulty can be mastered. With respect to the almost universal sterility of species when first crossed, which forms so remarkable a contrast with the almost universal fertility of varieties when crossed, I must refer the reader to the recapitulation of the facts

PC-Virginia-Francis-F373    Printed:    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. [Francis Darwin's copy]  London   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

PC-Virginia-Francis-F373    Printed:    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. [Francis Darwin's copy]  London   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

PC-Virginia-Francis-F373    Printed:    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. [Francis Darwin's copy]  London   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

The Complete Work of Charles Darwin Online [96] Moor Park (Mistaken Instinct) Ch X July 23 /59/ Observed number of ants by great nest by Wall, F. flava rufa or wood-ant carrying out of nest the pupæ-skins. They carried others about to 33 measured yards on road to Tall larch-tree; three ascended tree, once I watched so high up tree till out of sight.— One perhaps (I have now no doubt that was so) dropped skin at foot of tree; at last I then lost sight of it— In another part of Park, I watched