Daphnia, 205.
Darwin, Charles, 80, 100, 102, 115, 116, 117;
Origin of Species, 116, 124, 130, 132, 135;
Erasmus, 135, 136, 138, 142, 143.
Deer, 42;
fossil, of North America, 97, 98.
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.