Page:Popular Science Monthly Volume 4.djvu/609

 structures, that the whole change is wrought from a complete dominant power of the physical over the mental, to the reverse, viz., an entire dominant ascension, in some instances, of the moral and intellectual over the physical. In every vertebrate animal, then, there are two factors, the physical and mental; the facial angle is the typical expression or exponent of the relative strength or condition of each.

It may be observed that, with the ascension of these animals, the relative size of the brain-case, or skull, increases with a proportionate diminution of the bones of the face, and of the projection of the jaws in front of the orbits.

In the cold-blooded fish, the serpent, and the crocodile, the cavity for the brain is small, but little more than a prolongation of the canal for the spinal cord, with a disproportionate development of the organs of mastication, thus enabling them to execute the strongest instinct of the lower animals, namely, to slay and devour. In the bird class, the brain is somewhat larger, but is contained in the posterior part of the cranium, they manifesting but a slight mental superiority over the reptile. In the dog, over whom man is lord, and the noble horse, the brain is much larger; the facial line intersects at about a right angle with the base line, or vertebral axis. In these animals we begin to discover the rudiments of some of those more noble motives which are so abundantly lavished upon some of the higher animals.

The monkey and the anthropoid, or man-like apes, express in a very characteristic manner many of the mental attributes of the lower varieties of the human species. Nor is this to be wondered at, when we consider the close anatomical relation which subsists between the two, and the enormous development of the cerebral hemispheres as compared with the lower classes of the same type.

The profile of the idiot is the next introduced in the cut, to illustrate the Influence upon the size and shape of the cranium, or skull, that an arrest of brain-development has wrought, and which corresponds to the mental manifestations of its subject.

The other three profile views represent the savage, the half-civilized, and the cultivated races of man. The first of the three, the one next to the view of the idiot, is a drawing from a correct engraving of the celebrated North American Indian chief Black Hawk, and corresponds in brain capacity, facial angle, and mental powers, very nearly to the other savage races, viz., the Malayan and Ethiopian. The next that is represented in the cut is the half-civilized Mongolian race, illustrating very nicely the ratio of the two factors, physical and mental. The last is a representation of the highly-cultivated Caucasian race, and is a correct profile view of one of the most illustrious statesmen that this or any other nation ever possessed—that of Daniel Webster..

In the lowest of the type, the fish, we find the brain least developed, and the cerebral hemispheres, or instrument of thought, bearing