of ichthyosis,
with supernumerary digits, with a deficiency of digits and phalanges,
and in a lesser degree with various diseases, especially with
colour-blindness, and a haemorrhagic diathesis, that is, an extreme
liability to profuse and uncontrollable bleeding from trifling wounds.
On the other hand, mothers have transmitted, during several
generations, to their daughters alone, supernumerary and deficient
digits, colour-blindness, and other peculiarities. So that we see that
the very same peculiarity may become attached to either sex, and be
long inherited by that sex alone; but the attachment in certain cases
is much more frequent to one than the other sex. The same peculiarities
also may be promiscuously transmitted to either sex. Dr. Lucas gives
other cases, showing that the male occasionally transmits his
peculiarities to his daughters alone, and the mother to her sons alone;
but even in this case we see that inheritance is to a certain extent,
though inversely, regulated by sex. Dr. Lucas, after weighing the whole
evidence, comes to the conclusion that every peculiarity, according to
the sex in which it first appears, tends to be transmitted in a greater
or lesser degree to that sex.

A few details from the many cases collected by Mr. Sedgwick,[161] may
be here given. Colour-blindness, from some unknown cause, shows itself
much oftener in males than in females; in upwards of two hundred cases
collected by Mr. Sedgwick, nine-tenths related to men; but it is
eminently liable to be transmitted through women. In the case given by
Dr. Earle, members of eight related families were affected during five
generations: these families consisted of sixty-one individuals, namely,
of thirty-two males, of whom nine-sixteenths were incapable of
distinguishing colour, and of twenty-nine females, of whom only
one-fifteenth were thus affected. {73} Although colour-blindness thus
generally clings to the male sex, nevertheless, in one instance in
which it first appeared in a female, it was transmitted during five
generations to thirteen individuals, all of whom were females. A
haemorrhagic diathesis, often accompanied by rheumatism, has been known
to affect the males alone during five generations, being transmitted,
however, through the females. It is said that deficient phalanges in
the fingers