nces from the young
ape, while the latter departs as much from the dog in its development as
the man does. Startling as this last assertion may appear to be, it is
demonstrably true, and it alone appears to me sufficient to place beyond
all doubt the structural unity of man with the rest of the animal world,
and more particularly and closely with the apes."[220]

A few of the curious details in which man passes through stages common
to the lower animals may be mentioned. At one stage the os coccyx
projects like a true tail, extending considerably beyond the rudimentary
legs. In the seventh month the convolutions of the brain resemble those
of an adult baboon. The great toe, so characteristic of man, forming the
fulcrum which most assists him in standing erect, in an early stage of
the embryo is much shorter than the other toes, and instead of being
parallel with them, projects at an angle from the side of the foot, thus
corresponding with its permanent condition in the quadrumana. Numerous
other examples might be quoted, all illustrating the same general law.

_Diseases Common to Man and the Lower Animals._

Though the fact is so well known, it is certainly one of profound
significance that many animal diseases can be communicated to man, since
it shows similarity, if not identity, in the minute structure of the
tissues, the nature of the blood, the nerves, and the brain. Such
diseases as hydrophobia, variola, the glanders, cholera, herpes, etc.,
can be transmitted from animals to man or the reverse; while monkeys are
liable to many of the same non-contagious diseases as we are. Rengger,
who carefully observed the common monkey (Cebus Azarae) in Paraguay,
found it liable to catarrh, with the usual symptoms, terminating
sometimes in consumption. These monkeys also suffered from apoplexy,
inflammation of the bowels, and cataract in the eye. Medicines produced
the same effect upon them as upon us. Many kinds of monkeys have a
strong taste for tea, coffee, spirits, and even tobacco. These facts
show the similarity of the nerves of taste in monkeys and in ourselves,
and that their whole nervous system is affected in a similar way. Even
the parasites, both external and internal, that affect man are not
altogether peculiar to him, but belong to the same families or genera as
those which infest animals, and in one case, scabies, even the same
species.[221] These curious facts seem quite inconsistent with the idea
that man's