of the spine” (Nicholson), the spinal cord enters the cranial box at a perpendicular, and the head balances on the spinal column as on a pivot, all of which ensures the erect posture and bipedal progression in man. There are, moreover, no neck muscles to support the head in any other than the vertical position. There are many other differences, besides: the ape, for example, has no chin, while in man there is a marked mental protuberance; man has a slender waist, but the ape has a barrel-like torso without any waist; the ape has huge bony ridges for the attachment of muscles, _e.g._ the sagittal crest, the superciliary ridges, etc., while in man such features are practically absent. Ranke has given a very good summary of the chief anatomical differences between man and the anthropoid apes: “The gorilla’s head leaning forward, hangs down from the spinal column, and his chinless snout, equipped with powerful teeth, touches the breastbone. Man’s head is round, and resting on a free neck, balances unrestrained upon the spinal column. The gorilla’s body, without a waist, swells out barrel-shaped, and when straightened up finds no sufficient support on the pelvis; the back-bone, tailless as in man, but almost straight, loses itself without nape or neck formation properly so-called in the rear part of the head and without protuberance of the gluteal region in the flat thighs. Man’s body is slightly molded, like an hour-glass, the chest and abdomen meeting to form a waist where they are narrowest; the abdominal viscera are perfectly supported in the pelvis as in a plate; and elegance is decidedly gained by the double S-line, which, curving alternately convex and concave, passes from the crown through the neck and nape, down the back to the base of the spine and the gluteal region. The normal position of the gorilla shows us a plump, bear-like trunk, carried by short, crooked legs and by arms which serve as crutches and touch the ground with the knuckles of the turned-in fingers. The posture of the body is perfectly straight in man, it rests on the legs as on columns when he stands upright, and his hands hang down on both sides always ready for use. The gorilla is thickly covered with hair, while man’s body on the whole is naked.” (_Op. cit._, vol. II, p. 213.)