Darwin, and After Darwin, Volumes 1 and 3

Chapter XVI: Appendix: To Chapter V (2)

Text size

Doubtless there were internal plant-feeding larvae before there
were galls: and, indeed, we have geological evidence that boring
insects date very far back indeed. The primitive internal feeders,
then, were miners in the roots, stems, twigs, or leaves, such as
occur very commonly at the present day. These miners are
excessively harmful to plant-life, and form a class of the most
destructive insect-pests known to the farmer: they frequently cause
the death of the whole or part of the plant attacked. Now, we may
suppose that the secretions of certain of these insects caused a
swelling to appear where the larvae lived, and on this excrescence
the larvae fed. It is easy to see that the greater the excrescence,
and the greater the tendency of the larvae to feed upon it, instead
of destroying the vital tissues, the smaller is the amount of harm
to the plant. Now the continued life and vitality of the plant is
beneficial to the larvae, and the larger or more perfect the gall,
the greater the amount of available food. Hence natural selection
will have preserved and accumulated the gall-forming tendencies, as
not only beneficial to the larvae, but as a means whereby the
larvae can feed with least harm to the plant. So far from being
developed for the exclusive benefit of the larvae, it is easy to
see that, allowing a tendency to gall-formation, natural selection
would have developed galls exclusively for the benefit of the
plants, so that they might suffer a minimum of harm from the
unavoidable attacks of insects.

But here it may be questioned--have we proof that internal feeders
tend to form galls? In answer to this I would point out that
gall-formation is a peculiar feature, and cannot be expected to
arise in every group of internal feeders. But I think we can afford
sufficient proof that wherever it has arisen it has been preserved;
and further, that even the highly complex forms of galls are
evolved from forms so simple that we hesitate to call them galls at
all[66].

[66] _Entomologist_, March, 1890.

The paper then proceeds to give a number of individual cases. No doubt the principal objection to which Mr. Cockerell's hypothesis is open is one that was pointed out by Herr Wetterhan, viz. "the much greater facility afforded to the indirect action through insects, by the enormously more rapid succession of generations with the latter than with many of their vegetable hosts--oaks above all[67]." This difficulty, however, Mr. Cockerell believes maybe surmounted by the consideration that a growing plant need not be regarded as a single individual, but rather as an assemblage of such[68].

[67] _Nature_, vol. xli, p. 394.

[68] _Ibid._ vol. xli, pp. 559-560.

NOTE C TO PAGE 394.

The only remarks that Mr. Wallace has to offer on the _pattern of colours_, as distinguished from a mere _brilliancy of colour_, are added as an afterthought suggested to him by the late Mr. Alfred Tylor's book on _Colouration of Animals and Plants_ (1886). But, in the first place, it appears to me that Mr. Wallace has formed an altogether extravagant estimate of the value of this work. For the object of the work is to show, "that diversified colouration follows the chief lines of structure, and changes at points, such as the joints, where function changes." Now, in publishing this generalization, Mr. Tylor--who was not a naturalist--took only a very limited view of the facts. When applied to the animal kingdom as a whole, the theory is worthless; and even within the limits of mammals, birds, and insects--which are the classes to which Mr. Tylor mainly applies it--there are vastly more facts to negative than to support it. This may be at once made apparent by the following brief quotation from Prof. Lloyd Morgan:--

It can hardly be maintained that the theory affords us any adequate
explanation of the _specific_ colour-tints of the humming-birds, or
the pheasants, or the Papilionidae among butterflies. If, as Mr.
Wallace argues, the immense tufts of golden plumage in the bird of
paradise owe their origin to the fact that they are attached just
above the point where the arteries and nerves for the supply of the
pectoral muscles leave the interior of the body--and the
physiological rationale is not altogether obvious,--are there no
other birds in which similar arteries and nerves are found in a
similar position? Why have these no similar tufts? And why, in the
birds of paradise themselves, does it require four years ere these
nervous and arterial influences take effect upon the plumage?
Finally, one would inquire how the colour is determined and held
constant in each species. The difficulty of the Tylor-Wallace view,
even as a matter of origin, is especially great in those numerous
cases in which the colour is determined by delicate lines, thin
plates, or thin films of air or fluid. Mr. Poulton, who takes a
similar line of argument in his _Colours of Animals_ (p. 326), lays
special stress on the production of _white_ (pp. 201-202).

As regards the latter point, it may be noticed that not in any part of his writings, so far as I can find, does Mr. Wallace allude to the highly important fact of colours in animals being so largely due to these purely physical causes. Everywhere he argues as if colours were universally due to pigments; and in my opinion this unaccountable oversight is the gravest defect in Mr. Wallace's treatment both of the facts and the philosophy of colouration in the animal kingdom. For instance, as regards the particular case of sexual colouration, the oversight has prevented him from perceiving that his theory of "brilliancy" as due to "a surplus of vital energy," is not so much as logically possible in what must constitute at least one good half of the facts to which he applies it--unless he shows that there is some connection between vital energy and the development of striations, imprisonment of air-bubbles, &c. But any such connection--so essentially important for his theory--he does not even attempt to show. Lastly, and quite apart from these remarkable oversights, even if Mr. Tylor's hypothesis were as reasonable and well-sustained as it is fanciful and inadequate, still it could not apply to _sexual_ colouration: it could apply only to colouration as affected by physiological functions common to both sexes. Yet it is in order to furnish a "preferable substitute" for Mr. Darwin's theory of _sexual_ colouration, that Mr. Wallace adduces the hypothesis in question as one of "great weight"! In this matter, therefore, I entirely agree with Poulton and Lloyd Morgan.

INDEX

Accident, Darwin's use of the word, 334-340;
beauty due to, 408, 409.

Achromatin, 126-134.

Acquired characters, _see_ Characters.

_Acraea eurita_, 328.

Adaptation, facts of, in relation to theory of natural selection,
401-403, 411.

Adaptive characters, _see_ Characters.

AEsthetic sense in animals, 380-385;
_see_ Beautiful.

Agassiz, Prof. A., on fauna of the Mammoth cave, 70.

Alpine plants, 209, 210, 440-442.

_Amauris niavius_, 328.

_Amblyornis inornata_, 381-383.

_Amphioxus_, 137, 138, 145, 146.

Analogy, 38, 50-65, 176, 177, 347-350.

Anthropoid, _see_ Apes.

Antlers, 98-100, 167-169.

Ants, co-operative instincts of, 268;
leaf-cutting, 332;
keeping aphides, 292.

Ape, eye of, 75;
_appendix vermiformis_ of, 84-86.

Apes, ears of, compared with those of man, 88;
muscles of, 77, 82, 83;
feet of, 77, 78;
tail of, compared with that of man, 82-84;
hair of, compared with that of man, 89-91;
teeth of, compared with those of man, 92-94;
flattening of tibiae of, 95, 96.

Aphides, 292.

_Appendix vermiformis_ of man compared with that of orang, 84-86.

_Apteryx_, 68, 69.

_Archaeopteryx_, 171-173.

Arctic plants, 209, 210, 440-442.

Argyll, Duke of, on natural selection, 334-362.

Aristotle, his idea of scientific method, 1;
on classification, 23, 24.

Arm, distribution of hair on, in man and apes, 89-92.

_Arthropoda_, embryology of, 155.

Artificial selection, analogy of, to natural selection, 295-314;
pictorial representations of products of, 298-312.

Artiodactyls, 182-191.

Association, principle of, in aesthetics, 404-407.

Aster, 129-133.

Attraction-spheres, 128, 132, 133.

Australia, fauna of, 204, 205;
thriving of exotic species in, 286;
portrait of wild dog of, 304.

Azores, 224, 225.

Bacon, Lord, on scientific method, 2.

_Balanoglossus_, 147, 148.

_Baptanodon discus_, posterior limb of, 179-181.

Barriers, in relation to geographical distribution, 216-224.

Bats, 56, 224, 226, 240.

Battle, law of, 385, 386.

Baya-bird, 381.

Bear, skeleton of, 174;
feet of, 178.

Beautiful, the, sense of, in animals, 380-385;
standards of, 380-404;
Darwin's explanation of, in organic nature, 379-411;
facts of, in inorganic nature in relation to Darwin's theory of, in
organic, 404;
often determined by natural selection, 406, 407;
absent in many plants and animals, 408;
in nature often accidental, 409-411;
does not exist in organic nature as an end _per se_, 410, 411.

Bees, co-operative instincts of, 268.

Beetles, wingless, 68-70;
on oceanic islands, 224, 226, 229, 232.

Bell, Dr., on natural theology, 412.

Bell-bird, 396-398.

_Bembidium_, 233.

Bermudas, 225-227.

Biology, ideas of method in, 1-9.

Birds, ovum of, 124;
embryology of, 151-155;
paleontology of, 163-165, 172, 173;
brain of, 194-197;
as carriers of seed, eggs, and small organisms, 217, 218;
distribution of, 224-240;
aesthetic sense of, 380-385;
courtship of, 380-385.

_Birgus latro_, 62-65.

Blood, colour of arterial, 409.

Boar, _see_ Pig.

_Bombus lapidarius_, 331.

Bower-birds, play-houses of, 381-383.

Boyd-Dawkins, on flattening of early human tibiae, 96.

Brain, palaeontology of, 194-197.

British Isles, _see_ Islands.

Broca, 363.

Bronn, 363.

Budding, _see_ Germination.

Burdon-Sanderson, Prof., on electric organ of skate, 366.

Butler, Bishop, on argument from ignorance, 41.

Butterflies, defensive colouring of, 321-329.

Caesalpino, on classification, 24.

Calf, embryology of, 153.

Camel, foot of, 187-191.

Canadian stag, 196, 198, 199.

Canaries, portraits of, 303;
first mentioned by Gesner, 312, 313.

Cape de Verde Archipelagoes, fauna of, 228.

_Carcharias melanopterus_, 149.

Carruthers, on evolution, 436-442.

Caterpillars, colours and forms of, 319, 322-326.

Cattle, portraits of, 311.

Causation, natural, 402, 413, 414.

Caves, faunas of dark, 70-72.

Cell, physiological, and properties of the, 104-134.

_Cerura vinula_, 325, 326.

_Cervalces Americanus_, 196, 198, 199.

_Cervus dicrocerus_, _issiodorensis_, _matheronis_, _pardinensis_,
_Sedgwickii_, _tetraceros_, 168.

Chalmers, Dr., on natural theology, 412.

Chameleons, 317.

Characters, as adaptive, 273-276, 286-293, 349;
as specific, 274-276, 286-295;
as congenital and acquired, 274-276.

_Chasmorhynchus niveus_, and _C. tricarunculatus_, 396-398.

_Chelydra serpentina_, anterior limb of, 179-181.

Chick, embryology of, 153.

Chimpanzee, _see_ Apes.

Chlorophyll, 408.

_Chondracanthus cornutus_, 122.

Cirripedes, 430.

Classification, 23-49;
of organic nature by Genesis and Leviticus, 23;
artificial and natural, 24-26;
empirical rules of, 33-40;
Darwin on, 35, 36, 39,40;
form of, a nexus or tree, 29-32;
of organic forms like that of languages, 32;
single characters in relation to, 37;
aggregates of characters in relation to, 35-37;
adaptive and non-adaptive characters in relation to, 34, 35, 38, 39;
chains of affinities in relation to, 39-40;
biological differs from astronomical, 43.

Cockerell, on vegetable galls, 447, 448.

Colours, of plants and animals in relation to the theory of natural
selection, 317-332;
in relation to the theory of sexual selection, 391, 392, 394-396,
408-410, 448-450.

Colouring, _see_ Recognition marks, Protective, Seasonal, Warning, and
Mimicry.

Congenital characters, _see_ Characters.

Conjugation, of Protozoa, 115-117.

Continuity, principle of, in nature, 15-21.

Contrivance, Darwin's use of the word, 281.

Co-operation, mutual, of species alleged, 445-448.

Co-operative instincts, due to natural selection, 267, 269.

Cope, Professor, his table of geological formations, 163, 164;
his table of palaeontological development of feet, vertebral column, and
brain, 197.

Correlation of growth, 357-362.

_Cossonidae_, 233.

Courtship, _see_ Sexual Selection.

Crabs, 62-65, 139.

Cuttle-fish, 317.

Cuvier, on method in natural history, 3-4;
on monkeys, 429.

Cyst, _see_ Encystation.

Darwin, Charles, his influence on ideas of method, 1-9;
on classification, 35, 36, 39, 40;
on vestigial characters in man, 77, 86, 87, 92;
on imperfection of geological record, 165, and Appendix;
on means of dispersal, 216, 218;
on geographical distribution, 218, 219;
on fauna of the Galapagos Archipelago, 227, 228;
on natural selection, 252, 253, 255, 256, 286, 375, 376;
his use of such words as 'accident,' 'fortuitous,' 'purpose,'
'contrivance,' &c., 281, 334-340;
on sexual selection, 379-400.

Darwin, Erasmus, his theory of evolution, 253.

De Blainville, on the theory of descent, 258.

De Candolle, on classification, 34.

Deer, 98, 99, 167-169, 187, 191, 196, 198, 199.

Degeneration, 269, 270, 342.

Delamination, 139.

_Diadema euryta_, 330.

Diaster, 129-133.

Dingo, _see_ Dog.

_Dinornis_, 60, 61.

_Diptera_ mimicking _Hymenoptera_, 329.

Dog, dentition of, 39;
Dingo, 304;
domesticated varieties of, 305, 307;
hairless, 307;
skulls of, 307.

Duck, logger-headed, 68.

Dugong, eye of, 75.

Eagle, eye of, 75.

Ear, of whales, 65;
vestigial features of human, 76, 86-89;
of man and apes compared, 88.

Eaton, Rev. A. E., on wingless insects, 70.

_Echinodermata_, 125-127, 138, 155.

Ectoderm, 137-142.

Egg, _see_ Ovum.

Eimer, 363.

_Elaps fulvius_ imitated by non-venomous snakes, 330.

Electric organs, 365-373.

Elephant, foot of, 185, 186;
rate of propagation of, 261, 262.

Elk, 196-198, 199.

Embryo, human, _see_ Man.

Embryogeny, _see_ Ontogeny.

Embryology, 98-155.

Embryos, comparative series of, 152, 153.

_Encyclopaedia Britannica_, eighth ed., on instinct, 289-291.

Encystation of Protozoa, 115.

Endoderm, 137-142.

Equatorial plate, 129.

_Equus_, _see_ Horse.

_Erythrolamprus venustissimus_, 330.

Evolution, organic, fact of, Section I;
Method of, Section II;
ideas upon, prior to Darwin, 253-258;
divergent, 266, 267.

Ewart, Professor Cossar, on electric organ of skate, 364, 367.

Existence, _see_ Struggle for.

Eye, of octopus, 57, 58, 347-350;
absence of, in dark cave animals, 70-72;
nictitating membrane of, 74, 75;
development of, from cutaneous nerve-ending, 352-354.

Feet, 51-59, 66, 77-80, 174-192, 197.

Fertilization of ova, 127, 128;
of flowers by insects, 406.

Fish, embryology of, 143-155;
palaeontology of, 163, 165, 169-171;
brain of, 194-197;
distribution of, 224-246;
flying, 355.

Fission, reproduction by, 106, 107.

Flat fish, 317.

Float, _see_ Swim-bladder.

Flowers, fertilization of, by insects, 406.

Fly, imitating a wasp, 329.

Flying-fish, and squirrels, 355.

_Foraminifera_, 346.

Forbes, H. O., on scapulo-coracoid bones of _Dinornis_, 60.

Fortuitous, Darwin's use of the word, 340.

Fossils, _see_ Palaeontology.

Frogs, 317.

Galapagos Islands, 227-231, 236, 237.

_Galeus_, eye of, 75.

Galls, vegetable, 293-295, 446-448.

Gastraea, 137-140.

_Gastrophysema_, 138.

Gastrulation, 137, 140.

Gegenbaur, 147, 181.

Gemmation, reproduction by, 106, 107, 110, 111.

Generalization, 5.

Generalized types, 33.

Genesis, classification of organic nature in, 23.

Genial tubercle, 96.

Geographical distribution, 204-248; _see_ Glacial period, Barriers Transport of organisms, Oceanic islands, &c.

Geology, record of imperfect, 156-160, and Appendix;
_see_ Palaeontology.

Germs, prophetic, 272, 351-362.

Gesner, on classification, 24;
on canaries, 313.

Gill-arches, 146, 147, 150, 151.

Gill-slits, 146, 147, 150-153.

Gills, of young salamanders, 102;
origin of, in embryo, 144;
of fish, 150, 152.

Giraffe, neck of, in relation to Lamarck's theory, 254.

Glacial periods, effects of, on distribution of plants and animals,
209, 210, and Appendix.

Goose, Frizzled, portrait of, 304.

Gorilla, _see_ Apes.

Gray, Professor Asa, 337

Great-toe, in man and apes, 79-81.

Grouse, 317-319

Growth, correlation of, 357, 362.

_Gymnotus_, 365, 367.

Haeckel, on analogy between species and languages, 32;
on reproduction as discontinuous growth, 105, 106;
his ideal primitive vertebrate, 143, 144.

Hair, vestigial characters of, in man, 89-92.

Hales, 3.

Haller, 3.

Hamilton, Sir William, 272.

Hands, 51-55, 66, 80-82, 174-192.

Hare, 318, 319.

Hartmann, on flattening of early human tibiae, 96.

Harvey, on Lord Bacon's writings, 2.

Heart, development of, 154.

Heilprin, on skulls of deer, 198, 199;
on fossil shells, 201, 202.

Hen, ovum of, 122.

Heredity, in relation to classification, 28-31;
in relation to embryology, 98-102;
chromatin-fibres in relation to, 134;
in relation to theories of organic evolution, 253-255, 260-264, 377.

Hermit-crabs, 62-65, 288, 289.

_Heteromera_, 233.

Hilgendorf, on shells of _Planorbis_, 201.

_Hipparion_, 191, 192.

Hippopotamus, foot of, 187.

Hog, _see_ Pig.

Homology, 38, 50-65, 176, 177, 347-350, 357-359.

Homopterous insect, imitating leaf-cutting ants, 331, 332.

Hooker, Sir Joseph, on flora of St. Helena, 234.

Horns, 98-100, 167-169.

Horse, eye of, 75;
limb-bones of, 176, 177, 186, 188-192;
teeth of, 189-191;
portraits of domesticated breeds of, 309.

Human, _see_ Man.

_Humerus_, perforations of, in quadrumana and man, 94, 95.

Humming-birds, restricted to the New World, 211.

Hunter, 3;
on ear of whale, 65.

Huxley, Prof., on mechanical selection, 283;
on age of the earth, 435, 436;
on Dr. Whewell, 243.

Hyatt, on shells of _Planorbis_, 201.

_Hydra_, 111, 122.

_Hyrax_, foot of, 185, 186.

Ignorance, argument from, 41, 42, 49.

Illative Sense, 6.

Imitative colours, 317-323, 326-332.

Infant, feet of, 78, 79;
grasping power of, 81.

Infertility, inter-specific, in relation to natural selection, 374-376.

Insects, wingless, 68-70;
in primary formations, 163, Appendix;
on oceanic islands, 224-238;
in relation to galls, 293-295, 446-448;
defensive colouring of, 321-332;
fertilizing flowers, 406.

Instincts, always of primary use to species presenting them, 286-293.

Intercrossing, in relation to natural selection, 374-376.

Inutility of specific characters, in relation to natural selection,
374-376.

Islands, oceanic, 224-237;
British, 238-241.

Japan, hairless dog of, 101.

Jelly-fish, 119, 120.

_Kallima_, 323.

Karyokinesis, 112-114, 128-134.

Kepler, 272.

Kerguelen Island, flightless insects of, 70.

Kropotkin, Prince, on co-operative instincts, 269.

_Lagopus mutus_, 317, 318.

Lamarck, his method in natural history, 4;
his theory of evolution, 253-256.

Lamprey, 148.

Languages, classification of, resembles that of organic forms, 32.

Lankester, E. Ray, on karyokinesis, 129, 130.

Leaf insect, 322.

Le Conte, on geological succession of animal classes, 164, 165;
on types of tails, 169-173;
on fossil shells of _Planorbis_, 201;
his work on the relation of the theory of evolution to religious
thought, 412.

_Leptalis_, 328.

_Leuculmis echinus_, 122.

Leviticus, classification of organic nature in, 23.

Life, origin of, 15.

Linnaeus, on method in natural history, 3;
on classification, 26, 35-40.

Lion, skeleton of, 175;
feet of, 178.

Lizard, heart and gill-arches of, 150.

Lloyd Morgan, 273, 449, 450.

Lungs, development of, 154, 354.

Lyell, Sir Charles, on classification, 32;
on uniformitarianism, 258;
on rational species, 344;
on geological record, 420, 435, 439.

Madeira, wingless beetles of, 68-70;
peculiar beetles of, 226, 227.

Mammals, ovum of, 120-124;
embryology of, 151-155;
palaeontology of, 163, 165, 167, 180-199;
limbs of, 174-178, 182-199;
brain of, 194-199;
of Australia and New Zealand, 204, 205;
distribution of, on islands, 224-240.

Mammoth cave, fauna of, 70-72.

Man, nictitating membrane of, 75;
vestigial muscles of, 76, 77, 82, 83;
tail of, compared with that of apes, 82-84;
hair of, compared with that of apes, 89-92;
teeth of, compared with those of apes, 92-94;
perforation of humerus of, 94, 95;
flattening of ancient tibiae of, 95, 96;
embryology of, 119, 153;
hand of, 54;
arm of, 90, 91;
limb-bones of, 176, 177;
palaeontology of, 163, 165;
brain of, 194, 195;
Mr. Syme on, 346, 347.

Marsh, on palaeontology of the horse, 188-190.

Matthew, Patrick, on natural selection, 257.

Mesoderm, 142.

_Mesohippus_, 189, 192.

Metaphyta, 104, 105.

Metazoa, 104.

Method, ideas of, in natural history, 1-9;
of organic evolution, 252-261.

Meyer, Professor Ludwig, on helix of the human ear, 86.

Mimicry, 320-322.

Ministration, mutual, of species alleged, 445, 446.

_Miohippus_, 189.

Mivart, St. George, on eye of octopus, 57, 58, 348, 349;
on incipient organs, 362;
on mutual ministration of species, 445, 446.

Mollusca, shells of, 19, 199-203;
eye of, 57, 58;
embryology of, 155;
palaeontology of, 163, 165.

Monkeys, why all, do not become men, 342-344.

_Monotremata_, 205.

Morgan, _see_ Lloyd Morgan.

Morphology, 50-97.

Mule, portrait of, 309.

Multicellular organisms, 104.

Multiplication, _see_ Reproduction.

Naegeli, Prof., 337, 367.

Natural History, ideas of method in, 1-9.

Natural, interpretations as opposed to super-natural, 13-15;
causation, 13-15.

Natural selection, 252-378, 401-410;
Wells, Matthew, and Whewell on, 257, 258, 443-445;
statement of theory of, 256-284;
of evidences of, 285-332;
of criticisms of, 333-378;
relation of theory of, to religious thought, 401-410;
preserves types, 264-267;
cessation and reversal of, 270, 342;
errors touching theory of, 270-284, 332-364;
definition of, 275-376;
antecedent standing of theory of, 277-284;
Prof. Owen on, 333, 334;
Duke of Argyll on, 334-362;
Mr. Syme on, 340, 341, 345;
need not always make for improvement, 341-347;
homology and analogy in relation to, 347-350;
often determines beauty, 406, 407;
in relation to the formation of galls, 293-295. 446-448.

Nature, organic, 17;
inorganic, 1, 17, 18.

_Nauplius_, 138.

Neumayr, 19.

New Zealand, fauna of, 68, 204, 205;
thriving of exotic species in, 286.

Newman, on the Illative Sense, 6.

Newton, his idea of scientific method, 6.

Nictitating membrane, 74, 75.

Notochord, 146.

Novum Organon, the, on scientific method, 2.

Nucleus, 105, 112-134.

Nucleus-spindle, 129.

Nut-hatch, Syrian, ornamented nests of, 381.

Objective methods, 6.

Oceanic islands, _see_ Islands.

Octopus, eye of, 57, 58, 348-350.

_[OE]dicnemus crepitans_, 320.

Ontogeny, as recapitulation of phylogeny, 98-104.

Orang Outang, _see_ Apes.

_Oredon Culbertsoni_, 167.

Origin of Species, the, influence exercised by, on ideas of method, 1-9

_Orohippus_, 189.

Otaria, eye of, 75.

Ovum, 113-142;
human, 120-133;
amoeboid movements of young, 121-123;
segmentation of, 134, 135.

Owen, on ear of whale, 65;
on natural selection, 333, 334.

Owl, eye of, 75.

Paddle, _see_ Whale, and _Baptanodon discus_.

_Pagurus bernhardus_, 64.

Pain, in relation to the theory of evolution, 417.

Palaeontology, 159-203;
general testimony of, 156-165;
testimony of, in particular cases, 165-203;
consideration of objections to theory of evolution founded on grounds
of, 156-165, and Appendix.

_Palaeotherium_, 190, 191.

Paley, on natural theology, 98, 412.

_Paludina_, successive forms of, 19.

Panama, Isthmus of, 219.

_Panniculus carnosis_, 77.

_Papilio merope_, 330.

Parasites, of animals, devoid of beauty, 408.

Parsimony, law of, 272.

Parthenogenesis, 119.

Partridges, 319.

Peacock, tail of, 378;
courtship of, 383.

Peckham, Mr. and Mrs., on courtship of spiders, 388-390.

Perissodactyls, 182-192.

_Petromyzon marinus_, 148.

_Phenacodus primaevus_, 184, 185.

Phylogeny, _see_ Ontogeny.

Physiological selection, 376.

Pig, embryology of, 153;
feet of, 176, 187;
portraits of wild and domesticated, 312.

Pigeons, portraits of, 298, 299;
feather-footed, 359.

Pilot fish, 289.

_Planorbis_, transmutations of, 200, 201.

Pleasure and pain, in relation to the theory of evolution, 417.

_Plica semilunaris_, 75.

_Pliohippus_, 189.

Polar bear, skeleton of, 174;
feet of, 178.

Polar bodies, 125, 126.

Polar star, 129.

Polyps, 114.

Porpoises, 24, 25, 50.

Poulton, E. B., on warning colours, 325, 326;
on mimicry, 331, 332;
sexual selection, 400, 401, 449, 450.

Poultry, portraits of, 300-302.

Pronucleus, 126-128.

Prophetic types, 272, 351-362.

_Prophysema primordiale_, 140.

Protective colouring, 317-323.

_Protohippus_, 189.

Protozoa, 104.

Ptarmigan, 317, 318.

_Pterodactyl_, wing of, 56.

Purpose, Darwin's use of the word, 281, 340.

Puss moth, larva of, 325, 326.

Python, 66, 67.

Quadrumana, muscles of, 76, 82, 83;
perforations of humeri of, 94, 95;
hair on phalanges of, 91.

Rabbit, embryology of, 153;
multiplication of, in Australia, 286;
portraits of wild and domesticated breeds of, 308;
protective colouring of, 319, 320.

Radiate form, beauty of, 408, 409.

_Raia radiata_, and _batis_, 367-371.

Rats, species of, restricted to Old and New Worlds, 212;
British and Norwegian, 285, 286.

Rattle-snake, tail of, 289.

Recognition marks, 271-273.

Religion, in relation to Darwinism, 401-418.

Reproduction, different methods of, 106-117;
essence of sexual, 110;
foreshadowing of sexual in unicellular organisms, 115-117.

Reptiles, wing of flying, 56;
rudimentary limbs of, 67;
nictitating membrane of, 75;
branchial arches of, 150;
embryology of, 152;
palaeontology of, 163, 165, 178-180;
brain of, 194-197;
distribution of, 224-240.

_Rhinoceros_, foot of, 186.

Robinson, Dr L., on grasping power of an infant's hands, 80-82.

Rudimentary organs, 65-97.

Ruminants, palaeontology of, 167, 168.

Sacrum of man, compared with that of apes, 82-84.

_Sagitta_, 138.

Salamander, young of terrestrial, living in water, 102;
embryology of, 152.

Sandwich Islands, 234-237.

Science, method of, 1-9.

Sclater, W. L., on a case of mimicry, 331, 332.

Scorpion in Silurian formation, 163.

Sea, lamprey, 148;
destructive agency of the, 423, 424.

Seal, 51, 52, 75.

Seasonal changes of colour, 317-319.

Selection, value, 275;
by physical processes, 282, 283, 335. _See also_ Natural selection,
Artificial selection, Sexual selection, Physiological selection.

Sentiency, in relation to the theory of evolution, 417.

Sex, difference of, restricted to Metazoa and Metaphyta, 105.

Sexual reproduction, _see_ Reproduction.

Sexual selection, theory of, 277, 378-410;
statement and evidences of, 379-391;
criticisms of, 391-400;
includes law of battle with that of charming, 385, 386;
in relation to religious thought, 411-418;
Tylor's theory substituted for, by Wallace, 449, 450.

Shark, eye of, 75;
man-eating, 149;
and pilot-fish, 289.

Sheep, limb-bones of, 176, 177;
portraits of, 310.

Shells, of crabs, 62-64;
palaeontology of mollusks, 199-203;
land on oceanic islands, 224-240.

Silliman's Journal, on fauna of the Mammoth Cave, 70.

Skate, electric organ of, 364-373.

Skull, palaeontology of, 194-199;
of bull-dog compared with that of deer-hound, 307.

Slavonia, Tertiary deposits of, 18, 19.

Species, not eternal, but either created or evolved, 13;
named as such through absence of intermediate forms, 18-20;
groups of, in classification, 20,
and appearing suddenly in geological formations, 427-432, 437-440;
origin of, coincide in space and time with pre-existing and allied
species, 22;
geographical distribution of, 204-248;
extinct and living allied on same areas, 213;
life of, preserved by natural selection, 264-270;
not room for more than one rational, 344;
characters of, 274-276, 286-295, 374-376;
inter-sterility of allied, 374-376;
mutual ministration of alleged, 445, 446.

Specific characters, _see_ Characters.

Speculation, method of, 3-9.

Spencer, Herbert, on reproduction as discontinuous growth, 105, 106;
on use-inheritance, 253-256;
his failure to conceive the idea of natural selection, 257.

Spermatozoa, 123, 126-128.

Spiders, in primary formations, 163;
courtship of, 388, 389.

Sponges, 122, 139, 140.

Spontaneous, Darwin's use of the term, 340.

Spores, 115.

Squirrels, flying, 355.

Sterility, _see_ Infertility.

St. Helena, 231-234, 236-237.

St. Hilaire, 4.

Stick-insect, 322.

Stoat, 318.

_Strombus accipilrinus_, 201.

_Strombus Leidy_, 201.

Struggle for existence, 259-270.

Subjective, methods, 6.

Survival of the fittest, 335. _See also_ Natural selection.

Swim-bladder of fish, 154, 354.

Symbiosis, 269.

Syme, David, on the theory of natural selection, 340, 341.

Tail, types of, in fish and birds, 169-173.

Tasmanian wolf, dentition of, 39.

Teeth, of Tasmanian wolf, 39;
molar, of man, compared with those of apes, 92-94;
palaeontology of horses', 189-191.

Temperature, sense of, probable origin of that of sight, 353, 354.

Tennyson, 266.

Tibiae, flattening of, 95, 96.

Tissue-cells, _see_ Cell.

Toes, 79, 80; _see also_ Feet.

Tomes, C. S., on molar teeth of man and apes, 94.

_Torpedo_, 365, 367.

Tortoise, embryology of, 152, 154.

_Toxopneustes variegatus_, and _T. lividus_, 122.

Transport of organisms, means of, 207, 216-218.

Tribal fitness, as distinguished from individual, 267-269.

Trout, ovum of, 122.

Turtle, eye of, 75.

Tylor, Alfred, on colouration of animals, 448-450.

Type, preserved by natural selection, 264-269;
improvement of, by natural selection, 269, 270;
prophetic, 272, 351-362.

Types, as simple and generalized, 33.

Unicellular organisms, 104.

_Uraster_, 138.

Utility, of specific characters, 274, 275;
of incipient characters, 351-363;
of electric organs, 365-373.

Variation, in relation to natural selection, 263, 335-340, 377.

Verification, 6-9.

Vertebral column, embryology of 145, 146;
palaeontology of, 192, 193.

Vertebrated animal, ideal primitive, 143, 144;
embryology of, 143, 155.

_Vespa vulgaris_, 331.

Vestigial organs, 65-97.

_Volucella inans_, and _V. bombylans_, 329.

Wagner, Moritz, on geographical distribution, 216.

Wallace, A. R., on origin of species as coincident in time and space
with pre-existing and allied species, 22;
on wingless insects, 70;
on absence of hair from human back, and function of on arms of
orang, 89;
on geographical distribution, 207, 231, 232, 233, 243;
on natural selection, 256;
on recognition marks, 271-273;
on alleged deductive consequences of the natural selection theory,
273-276;
his theory of warning colours, 323, 324;
on sexual selection, 391-400, 450;
his principal defect in treating of animal colouration, 449, 450.

Warning colours, 323-326.

Wasp, imitated by a fly, 329.

Water-cress, multiplication of, in New Zealand, 286.

Weevils, on St. Helena, 232.

Weismann, his theory of heredity, 130, 134.

Wells, Dr., on natural selection, 257.

Wetterhan, Prof., on vegetable galls, 448.

Whales, 38, 50, 53, 54, 65, 180.

Whewell, on natural selection, 257, 258, 443-445.

Wings, 54-56, 60, 61, 68-70, 355.

Wolf, Tasmanian, dentition of, 34.

Wood, John, on vestigial muscles in man, 77.

Woodward, on fossil cirripedes, 431.

Woolner, on the human ear, 86.

Worms, embryology of, 155.

Wyman, Prof., on the great toe of human embryo, 79, 80.

_Zona pellucida_, 121.

Comments

Darwin, and After Darwin, Volumes 1 and 3Chapter XVI: Appendix: To Chapter V (2)

0%17 min left in chapter