persists more or less distinctly in man after maturity; and more
frequently in ancient than in recent crania, especially, as Canestrini
has observed, in those exhumed from the Drift, and belonging to the
brachycephalic type. Here again he comes to the same conclusion as in
the analogous case of the malar bones. In this, and other instances
presently to be given, the cause of ancient races approaching the lower
animals in certain characters more frequently than do the modern races,
appears to be, that the latter stand at a somewhat greater distance in
the long line of descent from their early semi-human progenitors.
Various other anomalies in man, more or less analogous to the
foregoing, have been advanced by different authors, as cases of
reversion; but these seem not a little doubtful, for we have to descend
extremely low in the mammalian series, before we find such structures
normally present. (41. A whole series of cases is given by Isidore
Geoffroy St.-Hilaire, Hist. des Anomalies, tom, iii, p. 437. A
reviewer ( Journal of Anatomy and Physiology, 1871, p. 366) blames me
much for not having discussed the numerous cases, which have been
recorded, of various parts arrested in their development. He says that,
according to my theory, every transient condition of an organ, during
its development, is not only a means to an end, but once was an end in
itself. This does not seem to me necessarily to hold good. Why should
not variations occur during an early period of development, having no
relation to reversion; yet such variations might be preserved and
accumulated, if in any way serviceable, for instance, in shortening and
simplifying the course of development? And again, why should not
injurious abnormalities, such as atrophied or hypertrophied parts,
which have no relation to a former state of existence, occur at an
early period, as well as during maturity?)
In man, the canine teeth are perfectly efficient instruments for
mastication. But their true canine character, as Owen (42. Anatomy of
Vertebrates, vol. iii. 1868, p. 323.) remarks, is indicated by the
conical form of the crown, which terminates in an obtuse point, is
convex outward and flat or sub-concave within, at the base of which
surface there is a feeble prominence. The conical form is best
expressed in the Melanian races, especially the Australian. The canine
is more deeply implanted, and by a stronger fang than the incisors.
Nevertheless, this tooth no longer serves man as a special weapon for
tearing his enemies or prey; it may, therefore, as far as its proper
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