A peculiar aptitude for procreation is sometimes hereditary. The children of prolific parents are themselves prolific. It is related that a French peasant woman was confined ten times in fifteen years. Her pregnancies, always multiple, produced twenty-eight children. At her last confinement she had three daughters, who all lived, married, and gave birth to children,--the first to twenty-six, the second to thirty-one, and the third to twenty-seven. On the contrary, sometimes a tendency to sterility is found fixed upon certain families, from which they can only escape by the most assiduous care. LONGEVITY. In the vegetable kingdom, the oak inherits the power to live many years, while the peach-tree must die in a short time. In the animal kingdom, the robin becomes grey and old at ten years of age; the rook caws lustily until a hundred. The ass is much longer-lived than the horse. The mule illustrates in a striking manner the hereditary tendency of longevity. It has the size of the horse, the long life of the ass. The weaker the ass, the larger, the stronger, and the shorter-lived and more horse-like the mule. It is also a curious and instructive fact, that this animal is the toughest after it has passed the age of the horse: the inherited influence of the horse having been expended, the vitality and hardiness of the ass remain. It is universally conceded, that longevity is the privileged possession of some lineages. That famous instance of old age, Thomas Parr, the best authenticated on record, may be mentioned in illustration. It is vouched for by Harvey, the distinguished discoverer of the circulation of the blood. Parr died in the reign of Charles the First, at the age of 152, after having lived under nine sovereigns of England. He left a daughter aged 127. His father had attained to a great age, and his great-grandson died at Cork at the age of 103. DEFORMITIES. Deformities are undoubtedly sometimes transmitted to the progeny. It is by no means rare to find that the immediate ancestors of those afflicted with superfluous fingers and toes, club-feet, or hare-lips, were also the subjects of these malformations. There are one or two families in Germany whose members pride themselves upon the possession of an extra thumb; and there is an Arab chieftain whose ancestors have from time immemorial been distinguished by a double thumb upon the right hand. Darwin gives many similar instances. A case of curious displacement of the knee-pans is recorded, in which the father, sister, son, and the son of the half-brother by the same father, had all the same malformation. PERSONAL PECULIARITIES.