s
physical change undoubtedly extends further than to the features only.
The whole constitution is modified.

A remarkable illustration of this fact is found in the frequent
observation that the children of a woman by a second husband often
resemble in appearance the first husband much more than their own father.
It has been observed that the children of negro women, even by husbands
of pure negro blood, are much lighter in color than usual if she has
had a child by a white man previously.

The same fact is observed in lower animals. In England, some years ago,
a cross was effected between a male zebra and several young mares. Not
only the hybrid colts resulting from this union, but all the colts
afterward foaled by the same mares, from other horses, were striped
like the zebra.

In view of these facts, it is evident that the system of the woman,
at least, may be profoundly affected in a similar manner by
constitutional weaknesses, as well as by other individual
peculiarities possessed by her husband.

No person suffering with a contagious or infectious disease has any
right to communicate the same to another. Indeed, it is the moral duty
of every person so affected to do all in his power for the protection
of others from the same cause of suffering.

_2. Persons having a marked hereditary tendency to disease must not
marry those having a similar tendency._

Every physician knows only too well the powerful influence of
hereditary causes in determining the length of human life. Persons,
one or both of whose parents have died of consumption, are very likely
to die of the same disease, and frequently at about the same age. The
children of such parents are commonly feeble and puny, and die early
if they survive infancy. When both parents possess the consumptive
tendency, the chance for life in the offspring is very poor indeed.
The same may be said of those suffering with cancer, epilepsy, insanity,
etc. Persons with a strong tendency to any one of the diseases mentioned
should in no case marry. If there is but a slight morbid tendency,
marriage may be admissible, but only with a partner possessing robust
health.

_3. Should cousins marry?_

Writers have devoted a good deal of attention to this subject, and we
have been shown statistics, reports of imbecile asylums, etc., for the
purpose of proving that the marriage of cousins results in the
production of idiots, and other defectives; but the results of more
car