The Descent of Man

much diversity in the teeth as in the features.
The chief arteries so frequently run in abnormal
courses, that it has been found useful for surgical
purposes to calculate from 1040 corpses
how often each course prevails. (3. 'Anatomy of
the Arteries,' by R. Quain. Preface, vol. i. 1844.)
The muscles are eminently variable: thus those
of the foot were found by Prof. Turner (4.
'Transactions of the Royal Society of Edinburgh,'
vol. xxiv. pp. 175, 189.) not to be strictly
alike in any two out of fifty bodies; and in some
the deviations were considerable. He adds, that
the power of performing the appropriate movements
must have been modified in accordance
with the several deviations. Mr. J. Wood
has recorded (5. 'Proceedings Royal Society,'
1867, p. 544; also 1868, pp. 483, 524. There is a
previous paper, 1866, p. 229.) the occurrence of
295 muscular variations in thirty-six subjects,
and in another set of the same number no less
than 558 variations, those occurring on both
sides of the body being only reckoned as one.