Charles Darwin _Frontispiece_ Fig. 1.—The Great Nebula in Orion 15 Fig. 2.—The Great Spiral Nebula 17 Fig. 3.—An Elongated Irregular Nebula 19 Fig. 4.—Lunar Craters: Hyginus and Albategnius 21 Fig. 5.—The Cluster in Hercules 23 Fig. 6.—A Pillar of Stratified Rocks 25 Fig. 7.—Segmentation of the Fertilized Ovum and Gastrulation 27 Fig. 8.—Cambrian Fossils and Upper Silurian Fossils 29 Fig. 9.—The Amphioxus 31 Fig. 10.—The Earliest Known Form of Fish and Three Other Early Forms of Fishes 33 Fig. 11.—Lampreys—The Mouth of a Lamprey 35 Fig. 12.—Lung Fishes 37 Fig. 13.—The Flying Fish 39 Fig. 14.—The Climbing Perch 41 Fig. 15.—The Evolution of the Frog 43 Fig. 16.—The Head of the Famous Archaegosaurus 45 Fig. 17.—The Ceratosaurus 47 Fig. 18.—The Archaeopteryx 49 Fig. 19.—The Duck-bill, known in Australia as the Platypus 51 Fig. 20.—A Kangaroo with her Young One in her Pouch 53 Fig. 21.—The Pariasaurus Baini 55 Fig. 22.—The Ring-tailed Lemur of Madagascar 57 Fig. 23.—The Slow Loris—another type of Lemur 59 Fig. 24.—The Baboon 61 Fig. 25.—The White-handed Gibbon 63 Fig. 26.—A Female Gorilla 65 Fig. 27.—Male Giant Gorilla 67 Fig. 28.—The Baldheaded Chimpanzee 69 Fig. 29.—The Skeleton of Man and of the Four Anthropoid Apes 71 Fig. 30.—Skull of the Fossil Ape-man of Java 73 Fig. 31.—A Restoration of the Neanderthal Man 75 Fig. 32.—Evolution of the Proboscidea 77 Fig. 33.—Eohippus, the “Dawn Horse,” from the Lower Eocene Rocks 79 Fig. 34.—Fossil Antlers 81 Fig. 35.—Antlers of One Deer at Different Stages of Their Development 83 Fig. 36.—Embryos of Four Mammals 85 Fig. 37.—Tail of a Six-Months-old Boy 87 Fig. 38.—The Vermiform Appendix in the Orang, in Man, and in the Human Foetus 89 Fig.