The Descent of Man

the reindeer, in which both sexes bear horns, in
comparison with their much later growth in the
other species in which the male alone bears
horns—we may conclude that one, though not
the sole cause of characters being exclusively
inherited by one sex, is their development at a
late age. And secondly, that one, though apparently
a less efficient cause of characters being
inherited by both sexes, is their development at
an early age, whilst the sexes differ but little in
constitution. It appears, however, that some
difference must exist between the sexes even
during a very early embryonic period, for characters
developed at this age not rarely become
attached to one sex.
SUMMARY AND CONCLUDING RE-
MARKS.
From the foregoing discussion on the various
laws of inheritance, we learn that the characters
of the parents often, or even generally, tend to