Page:Popular Science Monthly Volume 37.djvu/379

Rh same process continued through the successive generations of the human family. The distinctively human qualities acquired at the outset, together with the accumulation of inherited animal qualities, were handed down to the races that succeeded. They, in turn, bestowed all that had been bequeathed to them, together with their newly acquired race characteristics, to their descendants. Finally, the national characteristics, which in our time we may suppose to include all the traits that characterize civilized man, were differentiated.

Civilized man, therefore, inherits the accumulation of benefits that have come from the operation of the law of heredity through the long ages since life began upon the earth. In a deeper sense than we commonly think, we are the heirs of all the ages.

Man does not come into his full inheritance at the beginning of his existence. It is a fact of exceeding significance that, at the beginning of embryonic life, our bodies consist of nothing more than a single cell, precisely similar to the minute organisms with which life began upon the earth. It is as if man acknowledged the debt which he owes to these primordial living beings. But it is not only to the primal form of life that he makes this confession of affinity; for, as is well known, the successive stages of embryonic development represent the succession of type forms of animal life as they appeared upon the earth. Thus, man comes into his inheritance by degrees. At the beginning of his existence he possesses the characters of the primal forms of life; a little later, those of the second life-period—such as belong to the lower animals; still later, those of the third life-period—such as belong to the higher grade of animals. At a considerable time before birth he has already come into possession of all the animal qualities, and at birth the human physical characters are present. Then follows a more perfect development of the physical characters, and at the same time the acquirement of the higher human characteristics—the power of speech and the mental and moral faculties. Thus, in the unfolding embryo and in the growing child we have recorded in dim but unmistakable characters the history of the life of the earth.

A suggestion, looking to the future, here presents itself. The same agencies out of which has come the progress of the past are in operation now. It is, therefore, only in the course of nature that there should be a further progress. And as respects man, according to a law that has governed in the past, namely, that the most recently acquired characters of a type are most subject to progressive change, we may expect that advancement will be chiefly in respect to his higher powers—his intellectual, moral, and spiritual nature.