We cannot tell, because we cannot tell why either should
vary at all. Yet, as they both do vary in successive generations,--as
is seen under domestication,--and are correlated, we can only adduce
the fact. Darwin may be precluded from this answer, but we may say
that they vary together because designed to do so. A reviewer says
that the chance of their varying together is inconceivably small; yet,
if they do not, the variant individuals must perish. Then it is well
that it is not left to chance. As to the fact: before we were born,
nourishment and the equivalent to respiration took place in a certain
way. But the moment we were ushered into this breathing world, our
actions promptly conformed, both as to respiration and nourishment, to
the before unused structure and to the new surroundings.
"Now," says the "Examiner," "suppose, for instance, the gills of an
aquatic animal converted into lungs, while instinct still compelled a
continuance under water, would not drowning ensue?" No doubt.
But--simply contemplating the facts, instead of theorizing--we notice
that young frogs do not keep their heads under water after ceasing to
be tadpoles. The instinct promptly changes with the structure, without
supernatural interposition,--just as Darwin would have it, if the
development of a variety or incipient species, though rare, were as
natural as a metamorphosis.
"Or if a quadruped, not yet furnished with wings, were suddenly
inspired with the instinct of a bird, and precipitated itself from a
cliff, would not the descent be hazardously rapid?" Doubtless the
animal would be no better supported than the objection.
Pages:
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107