These facts have been brought clearly before the
reader by means of numerous diagrams, drawn to scale and exhibiting the
actual variations in inches, so that there can be no possibility of
denying either their generality or their amount. The importance of this
full exposition of the subject will be seen in future chapters, when we
shall frequently have to refer to the facts here set forth, especially
when we deal with the various theories of recent writers and the
criticisms that have been made of the Darwinian theory.
A full exposition of the facts of variation among wild animals and
plants is the more necessary, because comparatively few of them were
published in Mr. Darwin's works, while the more important have only been
made known since the last edition of _The Origin of Species_ was
prepared; and it is clear that Mr. Darwin himself did not fully
recognise the enormous amount of variability that actually exists. This
is indicated by his frequent reference to the extreme slowness of the
changes for which variation furnishes the materials, and also by his use
of such expressions as the following: "A variety when once formed must
again, _perhaps after a long interval of time_, vary or present
individual differences of the same favourable nature as before"
(_Origin_, p.
Pages:
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152