Living and Extinct (p. 740) thus answer the question:
"The distinctions between the Hominidæ and Simiidæ are chiefly relative, being greater size of brain and of brain-case as compared with the facial portion of the skull, smaller development of the canine teeth of the males, complete adaptation of the structure of the vertebral column to the vertical position, greater length of the lower as compared with the upper extremities, and greater length of the hallux or great toe, with almost complete absence of the power of bringing it in opposition to the other four toes. The last feature, together with the small size of the canine teeth, are perhaps the most marked and easily defined distinctions that can be drawn between the two groups."
This close analogy in bodily structure between man and the lower animals is strongly suggested by the facts of embryology, as all the homologous organs in the full-grown animal, such as the flipper of a whale, the wing of a bird and the hand of man, are developed from the same fundamental parts in the embryo. On similar grounds it can be proved that the human hand and foot had been developed from limbs which were somewhat similar to those of the quadrumana, which are specially adapted for arboreal life. It is of some significance to note that the great grasping power of the fore-limbs is still
