earance of
which it seems impossible to account for on the hypothesis of minute
indefinite variations. It is that of the mouth of the young kangaroo. In
all mammals, as in ourselves, the air-passage from the lungs opens in the
floor of the mouth behind the tongue, and in front of the opening of the
gullet, so that each particle of food as it is swallowed passes over the
opening, but is prevented from falling into it (and thus causing death from
choking) by the action of a small cartilaginous shield (the epiglottis),
which at the right moment bends back and protects the orifice. Now the
kangaroo is born in such an exceedingly imperfect and undeveloped
condition, that it is quite unable to suck. The mother therefore places the
minute blind and naked young upon the nipple, and then injects milk into it
by means of a special muscular envelope of the mammary gland. Did no
special provision exist, the young one must infallibly be choked by the
intrusion of the milk into the windpipe. But there _is_ a special
provision. The larynx is so elongated that it rises up into the posterior
end of the nasal passage, and is thus enabled to give free entrance to the
air for the lungs, while the milk passes harmlessly on each side of this
elongated larynx, and so safely attains the gullet behind it.

Now, on the Darwinian hypothesis, either all mammals descended from
marsupial progenitors, or else the marsupials, sprung from animals having
in most respects the ordinary mammalian structure. [Page 43]

On the first alternative, how did "Natural Selection" remove this (at least
perfectly innocent and harmless) structure in almost all other mammals,
and, having done so, again reproduce it in precisely those forms which
alone require it, namely, the Cetacea? That such a harmless structure _need
not_ be removed any Darwinian must confess, since a structure exists in
both the crocodiles and gavials, which enables the former to breathe
themselves while drowning the prey which they hold in their mouths. On Mr.
Darwin's hypothesis it could only have been developed where useful,
therefore not in the gavials(!) which feed on fish, but which yet retain,
as we might expect, this, in them superfluous but harmless formation.

On the second alternative, how did the elongated larynx itself arise,
seeing that if its development lagged behind that of the maternal
structure, the young primeval kangaroo must be choked: while without the
injecting power in the