The septum lucidum consists of gray matter. The corpus striatum, situated at the base of the lateral ventricles, nearly in the center of the brain, was from three eighths to half an inch in diameter in an ox which was dissected in Edinburgh. This is about the same amount as is found in the corpus striatum of the human brain. There would be lively times if it were possible for a mental faculty to occupy at once all the localities where gray matter is found!
None of the suppositions about certain qualities of mind inhering in particular portions of the brain have been proved, nor have they stood the tests of science.
The theories which have assumed that the cultivation of the intellect gives shape and size to the brain within and consequently to the skull without, advocates of which have not been wanting, have been disproved by the collected facts. "There is no proof," says Dr. J. C. Nott, in his Types of Mankind, "of the theory that the cultivation of the mind or of one set of faculties can give expansion or increased size of brain. The Teutonic races, in their barbarous state, two thousand years ago, possessed brains as large as now, and so with other races."
The St. Louis Globe Democrat of November 13, 1885, gives an account of some excavations on the Mount Ararat farm, east of Carrollton, Illinois, where the bones of thirty-two Indians or mound builders were unearthed. "They were not a diminutive race, as some people have supposed, some of the thigh bones being sixteen inches long, and some of the skulls twenty-four inches in circumference." A skull having a circumference of twenty-four inches means a head that measured from twenty-five to twenty-six and a half in life, when the cranium was covered with skin and muscles. The average head of white men in New York to-day is only twenty-two and a half inches round. So the culture of the white race for centuries has not developed their heads to near the size of those of the uncultured mound builders who inhabited America many centuries ago. Our own opinion is that cultivation by means of a thorough classical education, where the appetite is restrained, as usually occurs, tends rather to diminish the size of the head, by reducing the temporal muscles and the adipose tissue under the scalp.
The Engis skull is one of the most ancient known to exist, and belonged to the stone age, or about the same time as the Neanderthal skull. Professor Huxley describes it as being well formed, and considerably larger than the average of European skulls to-day in the width and height of the forehead and in the cubic capacity of the whole.
Quatrefages, in The Human Species, p. 312, says: "This skull (the Engis or Cro-Magnon), so remarkable for its fine proportion, is also remarkable for its capacity. According to M. Broca, who could only work under precautions calculated to diminish the amount, it is equal to at least 1,590 cubic centimetres (96.99 cubic inches). I have already remarked that this number is far higher than the mean taken from modern Parisians; it is equally so in comparison with other European nations."
These facts all conspire to prove that the cultivation of thousands of years has not increased the size of human skulls. In 1886, we measured many of the skulls unearthed at Pompeii, the remains of Romans who lived nearly two thousand years ago, and we found them on the average larger in every way, but especially in the forehead, than the skulls of Romans of this century.
In the museums of Switzerland we measured in 1887 several skulls of the ancient lake dwellers of that country, and found them larger in all respects, but particularly in the forehead, than those of the Swiss people of the last fifty years. The average circumference of the skulls we measured in the catacombs of Paris was twenty-one inches and a half, which is about an inch more than that of Parisians who have died within the past fifty years.
"The average internal capacity of the Peruvian skull is only seventy-three cubic inches; that of Toltec skulls, seventy-seven inches, and that of barbarous tribes, eighty-two inches; so that the extraordinary anomaly is presented of a larger brain being possessed by the barbarous tribes than by the nations who achieved no mean degree of civilization in Central America and Peru. The average European skull is ninety-three inches in bulk."[56] The author was informed by Mr. Lucien Carr, of the Ethnological Museum of Harvard University, that the capacity of the Peruvian skulls was about one hundred centimetres smaller than that of the skulls of any other people living in America at the same time. Yet that small-headed people was the most highly civilized of all.