You will be led to conclude that you are
observing a sudden change in structure such as is usually called a
sport.
Or in other words you may think that you are assisting at the
origination of a new variety. If you are familiar with the principle of
vicinism, you will refrain from such an inference and consider the
supposition of a hybrid origin. But in former times, when this principle
was still unknown and not even guessed at, it is evident that many
mistakes must have been made, and that many an instance, which until now
has been considered reliable proof of a so-called single variation, is
in fact only a case of vicinism. In reading the sparse literature on
sports, numerous cases will be found, which cannot stand this test. In
many instances crossing must be looked to as an explanation, [215] and
in other cases the evidence relied upon does not suffice to exclude this
assumption. Many an old argument has of late lost its force by this
test.
Returning to our starting point we may now state that regular reversions
to a specific type characterize a form as a variety of that species.
These reversions, however, are not due to an innate tendency, but to
unobserved spontaneous crosses.
[217]
LECTURE VIII
LATENT CHARACTERS
No organism exhibits all of its qualities at any one time.
Pages:
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221