Darwiniana | Page 3

fertilised by its proper pollen! On the other hand, the
famous Gaertner, though he took the greatest pains to cross the
Primrose and the Cowslip, succeeded only once or twice in several
years; and yet it is a well-established fact that the Primrose and the
Cowslip are only varieties of the same kind of plant. Again, such cases
as the following are well established. The female of species A, if
crossed with the male of species B, is fertile; but, if the female of B is
crossed with the male of A, she remains barren. Facts of this kind
destroy the value of the supposed criterion.
If, weary of the endless difficulties involved in the determination of
species, the investigator, contenting himself with the rough practical
distinction of separable kinds, endeavours to study them as they occur
in nature--to ascertain their relations to the conditions which surround
them, their mutual harmonies and discordancies of structure, the bond
of union of their present and their past history, he finds himself,
according to the received notions, in a mighty maze, and with, at most,
the dimmest adumbration of a plan. If he starts with any one clear
conviction, it is that every part of a living creature is cunningly adapted
to some special use in its life. Has not his Paley told him that that
seemingly useless organ, the spleen, is beautifully adjusted as so much
packing between the other organs? And yet, at the outset of his studies,
he finds that no adaptive reason whatsoever can be given for one-half
of the peculiarities of vegetable structure. 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 versâ_, and the more the natural
habits of animal and vegetable species are examined, the more do they
seem, on the whole, limited to particular provinces. But when we look
into the facts established by the study of the geographical distribution
of animals and plants it seems utterly hopeless to attempt to understand
the strange and apparently capricious relations which they exhibit. One
would be inclined to suppose _à priori_ that every country must be
naturally peopled by those animals that are fittest to live and thrive in it.
And yet how, on this hypothesis, are we to account for the absence of
cattle in the Pampas of South America, when those parts of