CHAPTER XVI.

CONCLUSIONS.

We have now, more or less fully, examined into the system of colouration in the living world, and have drawn certain inferences from the facts observed.

It appears that colouration began--perhaps as a product of digestion--by the application of pigment to the organs of transparent creatures. Supposing that evolution be true--and, if we may not accept this theory there is no use in induction whatever--it must follow that even the highest animals have in the past been transparent objects. This was admirably illustrated by Prof. Ray Lankester in a lecture on the development of the eyes of certain animals, before the British Association meeting at Sheffield, in which it was shown that the eyes commenced below the surface, and were useful even then, for its "body was full of light."

Granting this, it follows that the fundamental law of decoration is a structural one. Assuming, as we do, that memory has played a most important part in evolution, it follows that all living matter has a profound experience in decorating its organs--it is knowledge just as anciently acquired, and as perfectly, as the power of digestion. This colour was produced under the influence of light--so it is even in opaque animals.

With a knowledge so far reaching, we might expect that even in opaque animals the colouring would still follow structural lines, and there should still be traces of this, more or less distinct.

This is precisely what we do find; and, moreover, we sometimes get a very fair drawing of the important hidden parts, even where least expected, as in a cat's head, a snake's body, a dragon-fly's thorax, a spider's abdomen, a bird's skull.

But if animals thus learned to paint themselves in definite patterns, we might expect that when called upon to decorate _for the sake of beauty_ certain parts not structurally emphatic, they would adopt well-known patterns, and hence arose the law of repetition.

But with wider experience came greater powers, and the necessity for protection arising, the well-known patterns were enlarged, till an uniform tint is produced, as in the Java pig, or some repeated at the expense of others, as in the civets. But so ingrained is the tendency to structural decoration that even where modification has reached its highest level, as in the leaf-butterflies, some trace of the plan that the new pattern was founded on is recognisable, just as the rectangular basis can be traced in the arabesque ornaments of the Alhambra.

The pointing out of this great fact has seemed to us a useful addition to the great law of evolution. It supplements it; it gives a reason why.

Could he who first saw these points have read these final pages, it would have lightened the responsibility of the one upon whom the completion of the work has fallen. But he died when the work was nearly finished. The investigation is of necessity incomplete, but nothing bears such misstatements as truth, and though specialists may demur to certain points, the fundamental arguments will probably remain intact.

GLOSSARY.

ACETABULA. Lat. _acetabulum_, a little vessel. Sucking discs as on the tentacles of _Physalia_.

AORTA. Gr. The chief artery.

CEPHALOTHORAX. Gr. _kephale_, head; _thorax_, chest. The anterior division of the body in Crustacea and Arachnida, composed of the amalgamated segments of the head and thorax.

CILIA. Lat. _cilium_, an eyelash. Microscopic filaments having the power of vibratory movement.

C[OE]NOSARC. Gr. _Koinos_, common; _sarx_, flesh. The common stem uniting the separate animals of compound hydrozoa, &c.

CORPUSCLE. Lat. _corpusculum_, a little body. Small coloured bodies, as in the endoderm of hydra, p. 59.

DIFFERENTIATED. Modified into definite organs, or parts; as distinct from structureless protoplasm.

ECTODERM. Gr. _ektos_, outside; _derma_, skin. The internal layer or skin of the Coelenterata.

EFFERENT. Lat. _effero_, to carry out. A vessel which carries fluids out of the body is said to be efferent.

ENDODERM. Gr. _endon_, within; _derma_, skin. The inner layer or skin of Coelenterata. _See_ ECTODERM.

ENDOSARC. Gr. _endon_, within; _sarx_, flesh. The inner layer of sponges.

EPIDERMAL. Gr. _epi_, upon; _derma_, skin. Relating to the outer layer of skin. As applied to colour, surface pigment as distinct from hypodermal, or deep-seated colour.

GASTROVASCULAR CANAL. Gr. _gaster_, belly; Lat. _vasculum_, a little vessel. The canals or vessels in the umbrella (_manubrium_) of hydrozoa.

GONIDIA. Gr. _gonos_, offspring; _oidos_, like. Reproductive bodies in Sea-anemones.

HYDRANTH. Gr. _hudor_, water; _anthos_, flower. The bodies or polypes of hydroids which exercise nutritive functions. They were called polypites by Huxley.

HYDROPHYLLIA. Gr. _hudor_ and _phyllon_, a leaf. Leaf-like organs protecting the polypites of hydrozoa.

HYDROSOMA. Gr. _hudor_ and _soma_, body. The entire organism of a hydrozöon.

HYPODERMAL. Gr. _hypo_, beneath; _derma_, skin. In colour, such as lies beneath the surface, as distinct from epidermal.

LYTHOCYSTS. Gr. _lythos_, stone, _kystis_, a bladder. Sense organs in hydroids, consisting of transparent capsules inclosing round transparent concretions.

MANUBRIUM. Lat. a handle. The central polypite suspended from the interior of the umbrella of hydroids.

MESODERM. Gr. _mesos_, intermediate; _derma_, skin. The middle layer of sponges, &c.

MESOTHORAX. Gr. _mesos_ and _thorax_. The middle division of the thorax in insects, carrying the second pair of legs.

PERISTOME. Gr. _peri_, about; _stoma_, a mouth. The area surrounding the mouth in sea-anemones.

PNEUMATOCYST. Gr. _pneuma_, air; _kystis_ a bladder. The air-sac contained in the pneumatophore, see below.

PNEUMATOPHORE. Gr. _pneuma_; _phero_, to carry. The float of certain hydrozoa (_Physophoridæ_.)

POLYPITE. Gr. _polus_, many; _pous_, foot. The separate animal or zöoid of a hydrozöon. _See_ HYDRANTH.

PROTOPLASM. Gr. _protos_, first; _plasso_, I mould. The jelly-like matter which forms the basis of all tissues. It is identical with the _sarcode_ or flesh of protozoa.

SAC. Lat. _saccus_, a bag, a small cell.

SARCODE. Gr. _sarx_, flesh; _eidos_, form. The protoplasm of protozoa, &c., which see.

SPADIX. Lat. _spadix_, a broken palm branch. In zoology a hollow process occupying the axis of the generative buds of hydrozoa.

SPOROSAC. Gr. _spora_, a seed, and _sac_. The body containing the ova of hydrozoa.

SOMATIC FLUID. Gr. _soma_, the body. The fluid which contains digested food, and taking the place of blood, circulates through the body of hydrozoa.

TENTACLES. Lat. _tentaculus_, a little arm. The arms or prehensile organs of Sea-anemones, &c.

THREAD CELLS. Cells containing an extensible microscopic thread, possessing stinging properties, common among the _Coelenterata_.

THORAX. Gr. a breastplate. The chest.

INDEX.

PAGE

_Abyla_ 63

_Acanthometra_ 57

_Actinea Cari_, varieties of 66

---- _mesembryanthemum_ 54

_Acanthostratus_ 57

_Actinozoa_ 51, 52

_Æschna_ 77

_Agalma breve_ 64

_Agrion puella_ 77

_Aiptasia mutabilis_ 67

Albinism in butterflies 79

_Alcyonariæ_ 54

Allman, Prof., on Hydroids 59, 60

"Alps and Sanctuaries" quoted 36

_Amoeba_ 56

Amphibia 89

_Amphilonche_ 57

Andres, Dr., on Hydrozoa 65

_Anemonia sulcata_ 67

Anemones, Sea 52

Animals and Plants, origin of 36

---- classification of 49

_Anoechtochilus_ 95

Anteater 93

_Anthocaris belemia_ 41

---- _belia_ 42

---- _cardamines_ 41, 42

---- _euphemoides_ 43

---- _eupheno_ 42

---- _simplonia_ 42

_Apatura iris_ 46

---- larvæ of 81

_Arachnida_ 82

_Araschnia Levana_ 43, 45

---- _porima_ 43, 45, 79

---- _prorsa_ 43, 45

_Arctia_ 69

_Arachnocorys_ 57

Argus Pheasant 6, 39, 91

_Argynnis Lathonia_ 69

Armadillo 84

Arthropoda, colouration of 85

Ascidians 35

Automatic habits 9

_Arthorybia rosacea_ 64

Badger 93

_Begonia_ 95

Birds, colouration of 89

---- of Paradise 90

_Biston betularia_ 79

Black and White, production of 28

Blackwell, J., on British Spiders 82

_Blatta_ 14

Bougainvillea 16

Bower Birds 5

_Bunodes crassicornis_ 54

---- _gemmaceus_, varieties of 66

---- _rigidus_ 67

Burnet Moths 5, 69

Butler S., on inherited memory 9, 10, 11, 15

---- on origin of animals and plants 36

Butterflies, albinism in 79

---- classification of 74

---- sense organs of 30

---- varieties of 77

_Caladium_ 95

_Calathea_ 96

_Calycophoridæ_ 63

_Carcinus moenas_ 4

_Carpocanium_ 57

Cats, colouration of 17, 92

---- recognising form 32

Caterpillars, colours of 81

---- spiracular markings 22

_Cephalopoda_ 87

_Cerithium_ 86

Char 88

Chlorophyll in hydra 59

Cicada 77

_Cladococeus_ 57

Classification of animals 49

---- of butterflies 74

_Coelenterata_ 20

---- colouration in 51

_Coelodendrum_ 57

_Coenonympha davus_ 79

---- _pamphilus_ 79

Coenosarc 55

_Coleus_ 95

Colour and form 32

---- and transparency 53

---- epidermal 72

---- following structure 83, 91

---- hypodermal 53, 73

---- nature of 25

---- of day-and-night flying insects 47, 69

---- opaque 53

---- perception of 5, 23, 25, 32

---- uniform, why rare 28

Colouration 3

---- laws of 21, 51

---- of desert animals 4

---- of arthropoda 85

---- of coelenterata 51, 59

---- of insects 68

---- of invertebrata 49

---- of molluscs 85

---- of plants 94

---- of protozoa 51

---- of spiders 82

---- of vertebrata 88

---- sexual 5

---- varieties of 3

Contour feathers 91

_Conus_ 86

_Coppinia arcta_ 60

_Corallium rubrum_ 54

Corals 54

Correlation of teeth and hair 94

_Corynida_ 52

Cowries 86

Crab, shore 4

Croton 46

Cuttle-fishes 19, 87

_Cyllo leda_ 45

_Cynthia cardui_ 68

_Cypræa_ 86

_Cyrtidosphæra_ 57

Dallas, W. S., on butterflies 71

_Danais_ 72

---- niavius 30, 80

Darwin, C. 1, 2, 5, 9, 11, 14, 45, 47, 94

Darwin, Dr. E., cited 37

Deer 92

Deformity, antipathy to 32

_Deilephila Euphorbiæ_ 81

---- _galii_ 81

Descent with modification 1

Desert animals, colour of 4

_Dictyoceras_ 57

_Dictyophimus_ 57

_Diphyes_ 63

Disease, markings in 39, 44

Distant, W. L., on Malayan butterflies 80

Distinctive Colouration 3

Dogs recognising portraits 32

_Dracæna ferrea_ 96

Elephant, increase of 2

Engelmann on _Euglena_ 34

Epidermal colour 72

_Eresus cinnabarinus_ 82

_Eucecryphalus_ 57

_Eucrytidium_ 57

_Euglena viridis_ 34

Evolution 1-98

Eye-spots 45, 47

Fayrer, Sir W., on snakes 89

Feathers 91

Fishes, colours of 88

Foal, stripes on 46

_Foraminiferæ_ 56

Fuller, W. J., on aquatic larvæ 77

Gamopetalous flowers 96

Gegenbaur's "Comparative Anatomy" cited 82

General colouration 3

_Gloxinia_ 96

_Gomphina_ 77

_Gonepteryx Cleopatra_ 41, 42

---- _rhamni_ 40, 42

Gonophores 52

_Grapta interrogationis_ 79

_Gregarinidæ_ 56

Guinea-fowl 91

Haagen, Dr., on colour 53, 72

Habits 8

Haeckel, Prof., on _Radiolaria_ 57

Hair and teeth, correlation of 94

Hawk moths 69

Hebrides, colours of insects in 80

Heredity 2

Herpes 40, 93

Heteromorphism 78

Higgins, Rev. H. H. 39

Hoverer flies 84

Humming birds 90, 92

Hutchinson, Mr., on herpes 40

Huxley, Prof., on hydrozoa 63

_Hydra viridis_ 59

_Hydrida_ 59

Hydrozoa 51, 59

Hypodermal colour 53, 72

Identity of offspring and parent 11

Identity, personal 10

Inherited memory 8

Insects, colour in 68, 75

John Dory 89

_Kallima inachus_ 30, 80

Kentish Glory Moth 30

_Lamium galeobdolon_ 96

Lankester, Prof. Ray, on development of eyes 97

Large Copper Butterfly 68

Larvæ, colours of 45, 81

Laws of emphasis 21

---- exposure 18

---- heredity 2

---- multiplication 2

---- repetition 21, 22

---- structure 18

---- variation 2

Leaf-butterfly 16, 30

Leidy, Prof., on _Rhizopoda_ 56

Leopard 17, 92

_Leucophasia diniensis_ 41

---- _sinapis_ 41

"Life and Habit" cited 9

Light, reflected 26

---- sensibility to 33

---- waves 25

_Liminitis sibilla_ 43

Lion 17, 92

---- stripes on young 46

Lithocysts of hydroids 62

_Lucernaria auricula_ 65

_Lycæna dispar_ 68

_Lycosa agretyca_ 83

---- _allodroma_ 83

---- _andrenivora_ 83

---- _cambria_ 84

---- _campestris_ 83

---- _latitans_ 84

---- _picta_ 84

---- _piratica_ 84

---- _rapax_ 83

Mackerel 88

_Mactra_ 86

---- _stultorum_ 87

Madrepores 54

Mammalia, colouration in 92

_Margarita catenata_ 87

Measles 39

Medusæ 52, 65

Melanism in insects 79

Meldola, Prof. R., on Melanism 79

_Melitæa artemis_ 43

---- _athalia_ 43

Mimicry 3, 4

Mollusca 21

---- colouration in 85

Monstrosities, antipathy to 32

_Morphinæ_ 72

_Morpho_ 4

_Murex_ 86

Muscles of insects 71

_Nectarinea chloropygea_ 90

Newman, Mr., on varieties of butterflies 77

Newts 89

Nitzsch on feather-tracts 91

Nudibranchs 85

_Nymphalidæ_ 74

Oak Egger Moth 30

Ocelli 47

Ocelot 93

_Oliva_ 86

Opaque colouring 53

Organ-pipe coral 54

Origin of animals and plants 36

---- -- species 1

Orthopoecilism 78

Oxen 94

Painted Lady Butterfly 68

Pangenesis 12

_Papilio Ajax_ 79

---- _machaon_ 43, 68, 76, 78

---- ---- larva of 81

---- _merope_ 30, 76, 80

---- _nireus_ 14

---- _podalirius_ 43

_Paradisea Papuana_ 90

---- _regia_ 90

---- _speciosa_ 90

---- _Wallacei_ 90

---- _Wilsoni_ 90, 91

_Pavetta Borbonica_ 96

_Pecten_ 86

Pelargonium 96

Perch 88

Personal identity 10

_Physalia_ 63

---- _caravilla_ 64

---- _pelagica_ 64

---- _utriculus_ 64

_Physophoridæ_ 63

Plaice 88

Plants and animals, origin of 36

---- colour in 95

Pneumatophores 63

Portuguese Man o' War 63

Protective resemblance 3

_Protista_ 34

Protozoa 20

---- colouration in 51, 56

Python 89

_Radiolaria_ 57

Rarity of uniform colour 28

Ray Lankester, Prof., on Ascidians 35

Red Admiral Butterfly 29

Repetition, effects of 8

Reptilia, colouration in 89

Resemblance, Protective 3

_Rhizophora filiformis_ 64

_Rhizopoda_ 56

Rhododendron 96

Ringlet Butterflies, eye-spots of 47

Roach 88

Romanes, Prof., cited 33, 34

_Satyrus hyperanthus_ 79

Scales of insects, structure of 72

Scarlet Tiger Moth 5

Sea anemones 52

---- ---- colours of 67

Seasonal dimorphism 70

Sea squirts 35

_Segestria senoculata_ 83

Selection, sexual 5

Self-coloured flowers 28

Sense organs of Butterflies 30

_Sertularidæ_ 63

Sexual colours 4

---- selection 5

---- dimorphism 70

Shell, Structure of 85

Shore Crab 4

Simple variation in Butterflies 77

_Siphonophora_ 63

Small pox 39

Snakes, patterns of 89

Sollas, Prof., on Sponges 58

Soles 88

_Sparassus smaragdulus_ 82

Species, origin of 1

_Sphæronectes_ 63

_Sphingidæ_ 45, 69

Spiders, structure and colour of 82

Spiracles of larvæ 22

_Spondylus_ 86

Sponges 57

_Spongida_ 57

_Spongocyclia_ 57

Spots and Stripes 39

_Stephanomia amphitridis_ 63

Struggle for existence 2

Sun-birds 90

_Sus vittatus_ 46, 94

Sutton, Mr. Bland, on Herpes 40

Swallow-tailed Butterflies 68

_Syncoryne pulchella_ 62

Systems of colouration 51

Teeth and Hair, correlation of 94

_Thomisus cinereus_ 82

---- _floricolens_ 82

_Thomisus luctuosus_ 84

---- _trux_ 82

Thrush, increase of 2

Tiger 17, 92

---- Moths 69

_Tipula_ 33

Toucans 90, 92

Transparency and colour 53

_Trigonia_ 86

_Tubipora musica_ 54

_Tubularida_ 59

Tylor, A., on Specific change 10

_Vanessa Antiopa_ 76

---- _atalanta_ 29, 43, 69

---- _urticæ_ 77

Variation in insects 70

---- law of 2

---- simple, in Butterflies 77

_Velella_ 52, 65

Vertebrata, colouration of 88

_Viverridæ_ 94

Wallace, A. R., on sexual selection 5, 6, 14, 15

---- on colour 29

---- on abnormal structures 94

Warning colours 4

Wasps 84

Weir, J. Jenner, on variation in insects 78

Weismann, Dr., on Caterpillars 81

Wing of Butterfly, typical 70

---- patterns of 76

Woodpecker 91

Yellow Archangel 96

Zebra 92

_Zygæna_ 69

Transcriber's Notes:

Variations in spelling, punctuation and hyphenation have been retained except in obvious cases of typographical error.

"Haeckel" and "Hæckel" were used interchangeably and have been standardized to "Haeckel".

Image tags interrupting paragraphs have been moved.

Footnotes have been moved to end of chapters.

End of Project Gutenberg's Colouration in Animals and Plants, by Alfred Tylor