Page:Popular Science Monthly Volume 32.djvu/710

690 upon possessing and transmitting small hands, the outward and visible sign of long exemption from manual labor. The aristocracy of China pride themselves on the smallness of their feet. The implication is in each case the same. We often speak of "blue blood" without any clear idea of the meaning of the expression. The phrase probably arose from the recognition of the fact, that the aristocratic and luxurious classes, who are exempt from actual labor, possess a fine white skin, through which the veins show themselves clearly, and that this peculiarity is transmitted from generation to generation. It is a fact of history that Frederick William I of Prussia succeeded in producing a stock of gigantic grenadiers by matching his tallest soldiers with women of similar proportions.

No point of structure is too minute to afford instances of the law of inheritance. A little spot on the iris has been transmitted from parent to child. The possession of a few abnormally long hairs in the eyebrows has been known to characterize the various members of certain families; and the characteristic of a patch of prematurely gray hair has been transmitted through several generations. Many curious records exist of families which possessed and gloried in their scars, moles, and other family marks, faithfully transmitted from parent to child—a sort of secret hall-mark stamped by Nature to attest the genuineness of the line. Peculiarities in the structure, arrangement, and even in the chemical composition of the teeth, frequently run in families. The writer, among whose professional duties the frequent inspection of tongues holds a humble but not unimportant place, has remarked a notable peculiarity in the shape of that organ transmitted from mother to daughter.

Peculiarities in the expression of the face are frequently inherited. Many cases may be remarked where an inherited resemblance is quite latent when the features are in repose, but comes out with startling vividness when they are agitated by emotion. Among the acquaintances of the writer is a gentleman who, when smiling, exhibits a most peculiar and unusual arrangement of lines at the outer angle of the eyes, and this characteristic has been faithfully transmitted to his children.

When we turn to the lower animals, the instances of striking peculiarities being inherited are still more numerous, and have been recorded with greater care and accuracy. Every breeder and trainer is aware of the vast importance of the law of inheritance, and no instance is allowed to escape notice; but it is only in recent years that philosophers have become alive to the fact that in his physical nature man obeys the ordinary biological laws which prevail among the higher animals, and that among these laws the law of inheritance holds the first place. A breed of cattle once existed which possessed only one horn, and this was transmitted. A one-antlered stag has been known to propagate this peculiarity in his offspring. A rabbit