V. Recapitulation.
The anatomical gulf between men and apes does not exist. There are, in fact, no gulfs anywhere, only gradations. All chasms are completely covered by unmistakable affinities, in spite of the fact that the remains of so many millions of deceased races lie hidden beneath seas or everlastingly locked in the limy bosoms of the continents. There are closer kinships and remoter kinships, but there are kinships everywhere. The more intimate kinships are indicated by more definite and detailed similarities, and the more general relationships by more fundamental resemblances. All creatures are bound to all other creatures by the ties of a varying but undeniable consanguinity.
Man stands unquestionably in the primate order of animals, because he has certain qualities of structure which all primates have, and which all other animals have not: hands and arms and nails, a bagpipe stomach, great subordination of the cerebellum, a disc-like placenta, teeth differentiated into incisors, canines, and molars, and pectoral milk glands.
Man is more closely akin to the anthropoid apes than to the other primates on account of his immense brain, his ape-like face, his vertical spine, and in being a true two-handed biped. The manlike apes and men have the same number and kinds of teeth, the same limb bones and muscles, like ribs and vertebrae, an atrophied tail, the same brain structure, and a suspicious similarity in looks and disposition. Men and anthropoids live about the same number of years, both being toothless and wrinkled in old age. The beard, too, in both classes of animals appears at the same period of life and obeys the same law of variation in colour. Even the hairs on different parts of the bodies of men and anthropoids, as on the arms, incline at a like angle to the body surface. The hair on the upper arm and that on the forearm, in both anthropoids and men, point in opposite directions—toward the elbow. This peculiarity is found nowhere in the animal kingdom excepting in a few American monkeys.
Man’s mammalian affinities are shown in his diaphragm, his hair, his four-chambered heart, his corpus callosum, his non-nucleated blood-corpuscles, and his awkward incubation.
The fishes, frogs, reptiles, birds, and non-human mammals are human in having two body cavities, segmented internal skeletons, two pairs of limbs, skulls and spinal columns, red blood, brains, and dorsal cords; and in possessing two eyes, two ears, nostrils, and mouth opening out of the head. And finally all animals, including man, are related to all other animal forms by the great underlying facts of their origin, structure, composition, and destiny. All creatures, whether they live in the sea, in the heavens, or in subterranean glooms; whether they swim, fly, crawl, or walk; whether their world is a planet or a water-drop; and whether they realise it or not, commence existence in the same way, are composed of the same substances, are nourished by the same matters, follow fundamentally the same occupations, all do under the circumstances the best they can, and all arrive ultimately at the same pitiful end.