The Descent of Man

ed to me to investigate some striking or crucial
instances, and to rely on the result.
An excellent case for investigation is afforded
by the Deer family. In all the species, but one,
the horns are developed only in the males,
though certainly transmitted through the females,
and capable of abnormal development in
them. In the reindeer, on the other hand, the
female is provided with horns; so that in this
species, the horns ought, according to our rule,
to appear early in life, long before the two sexes
are mature and have come to differ much in
constitution. In all the other species the horns
ought to appear later in life, which would lead
to their development in that sex alone, in which
they first appeared in the progenitor of the
whole Family. Now in seven species, belonging
to distinct sections of the family and inhabiting
different regions, in which the stags alone bear
horns, I find that the horns first appear at periods,
varying from nine months after birth in