ture; he also discovers
rudimentary teeth, which are never used, in the gums of the young
calf and in those of the foetal whale; insects which never bite have
rudimental jaws, and others which never fly have rudimental wings;
naturally blind creatures have rudimental eyes; and the halt have
rudimentary limbs. So, again, no animal or plant puts on its perfect
form at once, but all have to start from the same point, however various
the course which each has to pursue. Not only men and horses, and cats
and dogs, lobsters and beetles, periwinkles and mussels, but even the
very sponges and animalcules commence their existence under forms which
are essentially undistinguishable; and this is true of all the infinite
variety of plants. Nay, more, all living beings march side by side along
the high road of development, and separate the later the more like they
are; like people leaving church, who all go down the aisle, but having
reached the door some turn into the parsonage, others go down the
village, and others part only in the next parish. A man in his
development runs for a little while parallel with, though never passing
through, the form of the meanest worm, then travels for a space beside
the fish, then journeys along with the bird and the reptile for his
fellow travellers; and only at last, after a brief companionship with
the highest of the four-footed and four-handed world, rises into the
dignity of pure manhood. No competent thinker of the present day dreams
of explaining these indubitable facts by the notion of the existence of
unknown and undiscoverable adaptations to purpose. And we would remind
those who, ignorant of the facts, must be moved by authority, that no
one has asserted the incompetence of the doctrine of final causes, in
its application to physiology and anatomy, more strongly than our own
eminent anatomist, Professor Owen, who, speaking of such cases, says
('On the Nature of Limbs', pp. 39, 40): "I think it will be obvious that
the principle of final adaptations fails to satisfy all the conditions
of the problem."

But, if the doctrine of final causes will not help us to comprehend the
anomalies of living structure, the principle of adaptation must surely
lead us to understand why certain living beings are found in certain
regions of the world and not in others. The palm, as we know, will not
grow in our climate, nor the oak in Greenland. The white bear cannot
live where the tiger thrives, nor 'vice v