the sex, usually the female, in which they are rudimentary or wanting is
capable of transmitting them to offspring, and also is capable of
developing them more or less completely when the ovaries are removed,
atrophied or diseased. If we state these facts in the terms of our present
conceptions of chromosomes and determinants or factors, we must say that
the factors for these characters are present in the chromosomes of both
male and female gametes. The question then is, how did these factors
arise? If they were mutations not caused by any influence from the
exterior, what is the reason why these particular characters which alone
have an adaptive relation to the sexual or reproductive habits of the
animal are also the only characters which are influenced by the hormones
of the reproductive organs? The idea of mutations implies neither an
external relation nor an internal relation in the organ or character; but
these characters have both, the external relation in the function they
perform in the sexual life of the individual, the internal relation in the
fact that their development is affected by the sexual hormones. There is
no more striking example of the inadequacy of the current conceptions of
Mendelism and mutation to cover the of bionomics and evolution.

The truth is that facts and experiments within a somewhat narrow field
have assumed too much importance in recent biological research. No
increase in the number of facts or experimental results of a particular
class will compensate for the want of sound reasoning and a comprehensive
grasp of the phenomena to be explained. The coexistence of the external
and the internal relation in the characters we are considering suggests
that one is the cause of the other, and as it is obvious that the relation
for instance of a stag's antlers to a testicular hormone could not very
well be the cause of the use of the antlers in fighting, the reasonable
suggestion is that the latter is the cause of the former. We have already
seen that the development and shedding of the antler are processes of