an instinct dating far back to the time when the ancestors of the ass were exclusively desert animals, and so unaccustomed to the sight of running water as to be confused and terrified by it. If any one observes a field of lambs at play, he will notice with what delight they frisk upon any hillock within their reach. Here we have probably a trace of the time when the progenitors of our sheep were Alpine animals, and possessed the habits of the chamois.
In the realm of disease, the facts of inheritance are most numerous, and are daily accumulating. Here they are no longer, alas, curious and amusing, but terrible, fateful, overwhelming. No fact of Nature is more pregnant with awful meaning than the fact of the inheritance of disease. It meets the physician on his daily rounds, paralyzing his art, and filling him with sadness. The legend of the ancient Greeks pictured the malignant Furies pursuing families from generation to generation, and rendering them desolate. The Furies still ply their work of terror and death; but we have stripped them of the garb which superstition threw around them, and they now appear to our eyes in the more intelligible but not less awful form of hereditary disease. Modern science, which has cast illumination into so many dark corners of Nature, has shed a new and still more lurid light on the words of the Hebrew Scripture: "The sins of the fathers shall be visited upon the children unto the third and fourth generation." Instances of hereditary disease abound on every hand. Fully fifty per cent of cases of gout are inherited. The proportion is not much less in that fell destroyer of families, our national scourge, consumption. Cancer and scrofula run strongly in families. Insanity is hereditary to a marked degree; but fortunately, like many other hereditary diseases, tends to wear itself out, the stock becoming extinct. Nearly all defects of sight are occasionally inherited. Sir Henry Holland says truly that "no organ or texture of the body is exempt from the chance of being the subject of hereditary disease." Probably most chronic diseases which permanently modify the structure and functions of the body are more or less liable to be inherited.
The important and far-reaching practical deductions from such facts—affecting so powerfully the happiness of individuals and families and the collective welfare of the nation—will be obvious to reflective minds, but can not be dwelt upon In the present article.—Chambers's Journal.
