Part 23

Development, 54; a natural process, 56.

De Vries, 145, 146; his mutation theory, 147, 148.

Dinosaurs, 94.

Distribution, geographical, 32.

Dogs, 38, 39; embryo of, 66; varied forms of, 137; pointer, sheep-dog, instincts of, 208; intelligence of, 208, 209.

Dubois, 173.

Ducksbill, or Ornithorhynchus, bottom of mammalian scale, 43.

Ducksworth, 184.

Eagle, 44.

Earthquake, 85.

Echidna, bottom of mammalian scale, 43.

Ectoderm, 255.

Egg, of common fowl, 60; of frog, 68; nuclei contains factors of development, 71; 144, 145; human, 231.

Eimer, 148.

Elements, chemical, 15.

Elephant, 41; place in zooelogical science, 95; 96, 97; age of, 124.

Embryo, of frog, 58; of chick, 60-62, 63, 64, 65; embryos of carnivora, rodents, hoofed animals alike in earlier development, 65; of cat, dog, rat, sheep, rabbit, squirrel, cattle, pig, 65; of skate, shark, hammerhead, 66; the human, 168, 170, 171; of birds, reptiles, amphibia, 171; human hemispheres of brain like adult cat or dog, 215.

Embryology, 32, 33, 34; of no form fully understood, 57; general principles of, 57-67; embryonic agreement, 65; of insects, 67; weight of facts of, 69; comparative, a distinct division of zooelogy, 70, 71; 76, 94, 100; evidence of, 170; of mind, 202, 214; in early stages of human, no nervous system present, 214; development of, 215.

English sparrow, 123, 127.

Environment, 111, 112; influences of, 126; determines mode of life of a race, 213.

Epoch, Glacial, 86; Silurian and Devonian, rich array of types, 93; Cenozoic, 96.

Erosion, 89.

Eskimo, picture-writing, 223.

Ethics, 281; biological, 283; natural, 284; evolution of, 285.

Ethnology, 177.

Evolution, the Doctrine of, 1; is it a science, 3; the conception of, 8; organic, 10-12; 31, 32; evidence of, 54, 95; of amphibia, 62; of birds, 63; of protozoa, 69; theory of, supported by palaeontology, 76; cosmic, 84; biological evidence of, 91; three important elements of, 109; adaptation, variation and inheritance, 110; mechanical, 109; dynamics of, 109; second element of, 122; human, 150-196; 174; physical, of man, falls into two groups, 153; of human races, 176; racial, 177, 178; mental, 197-240; human faculty as a product of, 212; mental as real as physical, 214; of brain, 214-217; of art of writing, 223; method of mental, 231; social, 241; of societies of insects, 258; human, biological interpretation of, 267-274; of higher human life, 278-311; of ethics, 285; final conception of, 307-311.

Factors, primary, secondary, 110; three kinds, 111; congenital, 113.

Falls of St. Anthony, 86.