Page:Darwinism by Alfred Wallace 1889.djvu/506

 Cope, Dr. E.D., on non-adaptive characters, 131

on fundamental laws of growth, 420

on bathmism or growth-force, 421

on use producing structural change, 422

on law of centrifugal growth, 422

on origin of the feet of ungulates, 423

on action of animal intelligence, 425

Correlations in pigeons, horses, etc., 140

Corvus frugilegus, 2

corone, 2

Coursers, figures of secondary quills, 224

Cowslip, two forms of, 157

Crab, sexual diversity of colour of, 269

Cretaceous period, dicotyledons of, 400

Crisp, Dr., on variations of gall bladder and alimentary canal, 69

Crosses, a cause of variation, 99

reciprocal, 155

Cross-fertilisation, modes of securing, 310

difference in, 155

Crossing and changed conditions, parallelism of, 166

Cruciferæ, variations of structure in, 80

Cuckoo, eggs of, 216

Cuckoos mimick hawks, 263

Cultivated plants, origin of useful, 97

Curculionidæ mimicked by various insects (figs.), 260

Curves of variation, 64

D

, Professor, on the permanence of continents, 342

Danaidæ little attacked by mites, 235

mimicry of, 246

Darwin, change of opinion effected by, 8

the Newton of Natural History, 9

his view of his own work, 10

on the enemies of plants, 16

on fir-trees destroyed by cattle, 17

on change of plants and animals caused by planting, 18

on absence of wild cattle in Paraguay, 19

on cats and red clover, 20

on variety of plants in old turf, 35

on the beneficent action of the struggle for existence, 40

on variability of wild geraniums, 79

on variability of common species, 80

his non-recognition of extreme variability of wild species, 82

on races of domestic pigeon, 90

on constitutional variation in plants, 95

on unconscious selection, 96

on a case of divergence, 105

on advantage of diversification of structure in inhabitants of one region, 110

on species of plants in turf, 110

on isolation, 119

on origin of mammary glands, 129

on eyes of flatfish, 129

on origin of the eye, 130

on useless characters, 131

on use of ears and tails, 136

on disappearance of sports, 140

on tendency to vary in one direction, 141

on rare perpetuation of sports, 142

on utility of specific characters, 142 (note)

on importance of biological environment, 148

on variable fertility of plants, 155

on fertile hybrids among plants, 164