of the mother, as will be shown
hereafter.
LATE MANIFESTATIONS OF THE EFFECTS OF INHERITANCE.
Not only are diseases inherited which make their appearance at birth,
but those which defer their exhibition until a certain period of life
corresponding with that at which they showed themselves in the parents.
Thus in the Lambert family, before referred to, the porcupine
excrescence on the skin began to grow in the father and sons at the same
age, namely, about nine weeks after birth. In an extraordinary hairy
family, which has been described, children were produced during three
generations with hairy ears: in the father, the hair began to grow over
his body at six years old; in his daughter somewhat earlier, namely, at
one year; and in both generations the milk teeth appeared late in life,
the permanent teeth being deficient. Greyness of hair at an unusually
early age has been transmitted in some families. So, also, has the
premature appearance of baldness.
HOW TO AVOID THE TENDENCY OF INHERITANCE.
These facts suggest the practical consideration, that in those diseases
the predisposition to which alone is inherited, and which break out only
after a lapse of time, it is often altogether possible to prevent the
predisposition being developed into positive disease. Thus, for
instance, the inherited tendency to _consumption_ remains asleep in the
system until about the age of puberty, or later. Therefore, by the use
of a diet in which animal food forms a large portion, properly
regulated, and systematic exercise in the open air, the practice of the
long inhalations before recommended, warm, comfortable clothing,
together with a residence, if practicable, during the changeable and
inclement seasons of the year, in an equable climate, we can often
entirely arrest the development of the disease. Prevention here is not
only better than cure, but often all that is possible. Those in whom the
disease has become active, must too often, like those who entered
Dante's infernal regions, 'abandon hope.' Let our words of caution
therefore be heeded.
When there is reason to believe that an individual possesses an inherent
tendency to any disease, it is the duty of the medical adviser to study
the constitution of the patient thoroughly, and after such study to
recommend those measures of prevention best suited to avert the
threatened disorder. Above all, let the physician look closely to the
child at the period of life when any
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