Whatever theory of instinct may be finally fixed upon as the most
correct and philosophical, (to account for the migratory movements of
birds,) it is obvious that we cut rather than untie the gordian knot
when we talk of the foresight of the brute creation. We might as well
talk of the foresight of a barometer. There can be little doubt that
birds, prior to their migratory movements, are influenced by
atmospherical changes, or other physical causes, which, however beyond
the sphere of our perceptions, are sufficient for their guidance. That
they are not possessed of the power of divination may be exemplified by
the following instance. The winter of 1822 was so remarkably mild
throughout Europe, that primroses came generally into flower by the end
of December,--rye was in ear by the middle of March, and vines, in
sheltered situations, blossomed about the end of that month,--so that an
assured and unchecked spring was established at least four or five weeks
earlier than usual;--yet neither the cuckoo nor the swallow arrived a
single day before their accustomed periods. They are indeed, beautifully
and wisely directed,--"Yea, the stork in the heavens knoweth her
appointed times; and the turtle, and the crane, and the swallow, observe
the time of their coming."--(From a delightful paper upon American
Ornithology, in the _Quarterly Review_, just published.)
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