The most splendid specimen of the Caucasian race that the civilized world can show to-day has no more organs, bones, muscles, arteries, veins, or nerves than those which are found in the lowest savage. He makes a different use of them, and that use has changed their development, and to some extent has modified stature, physical, intellectual, and moral, and many other attributes; as climate and habits of life have modified complexion, the diseases to which the human frame is liable, and many other peculiarities. But if we take historic man, we find that in all the physical features of his animal construction that constitute him a species, he has been essentially the same animal in all states of civilization or barbarism; and unless we boldly assume that the prehistoric man was an animal born with a coat of hair all over his body, and that clothing was resorted to as the hair in successive generations disappeared, we can have no very strong reason for believing that the human body has been at any time an essentially different structure from what it is now. Even in regard to longevity or power of continued life, if we set aside the exceptional cases of what is related of the patriarchs in the biblical records, we do not find that the average duration of human life has been much greater or much less than the threescore and ten or the fourscore years that are said to have been the divinely appointed term. As to what may have been the average duration of life among prehistoric men, we are altogether in the dark.