nds to wholesome efficiency and healthful endurance.

TRANSMISSION OF LIFE.

As has been already stated in the chapter on Biology, reproduction of
the species depends upon the union of a sperm-cell with a germ-cell, the
male furnishing the former and the female the latter. It is a well-known
fact that the marriage of persons having dissimilar temperaments is more
likely to be fertile than the union of persons of the same temperaments;
consanguineous marriages, or the union of persons nearly related by
blood, diminish fertility and the vigor of the offspring. Upon this
subject Francis Galton has given some very interesting historical
illustrations in his well-known work, entitled "Hereditary Genius." The
half-brother of Alexander the Great, Ptolemy I, King of Egypt, had
twelve descendants, who successively became kings of that country, and
who were also called Ptolemy. They were matched in and in, but in nearly
every case these near marriages were unprolific and the inheritance
generally passed through other wives. Ptolemy II married his niece, and
afterwards his sister; Ptolemy IV married his sister. Ptolemy VI and VII
were brothers, and they both consecutively married the same sister;
Ptolemy VII also subsequently married his niece; Ptolemy VIII married
two of his sisters in succession. Ptolemy XII and XIII were brothers,
and both consecutively married their sister, Cleopatra. Mr. Galton and
Sir Jas. Y. Simpson have shown that many peerages have become extinct
through the evil results of inter-marriage. Heiresses are usually only
children, the feeble product of a run-out stock, and statistics have
shown that one-fifth of them bear no children, and fully one-third never
bear more than one child. Sir J.Y. Simpson ascertained that out of 495
marriages in the British Peerage, 81 were unfruitful, or nearly one in
every six; while out of 675 marriages among an agricultural and
seafaring population, only 65 were sterile or barren, or a little less
than one in ten.

While the marriages of persons closely related, or of similar
temperaments are frequently unfruitful, we would not have the reader
understand that sterility, or barrenness, is usually the result of such
unions. It is most frequently due to some deformity or diseased
condition of the generative organs of the female. In the latter part of
this work may be found a minute description of the conditions which
cause barrenness, together with the methods of treatment