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The excerpt represents the core issue or deciding factor on which you must meditate, and is drawn from Expression of Emotion in Man and Animals by Charles Darwin: [19] `Quarterly Journal of Microscopical Science,' 1853, vol. i. p. 262.
We here encounter a great difficulty. How can the contraction of
the unstriped and involuntary _arrectores pili_ have been co-ordinated
with that of various voluntary muscles for the same special purpose?
If we could believe that the arrectores primordially had been
voluntary muscles, and had since lost their stripes and become involuntary,
the case would be comparatively simple. I am not, however, aware that
there is any evidence in favour of this view; although the reversed
transition would not have presented any great difficulty,
as the voluntary muscles are in an unstriped condition in the embryos
of the higher animals, and in the larvae of some crustaceans.
Expression of Emotion in Man and Animals |
