Half an hour’s walk by our neighbouring river will be sure to afford us a chance of seeing a water-ousel. Every reach contains a pair, and as they never leave the river-bed we have but to walk along the bank and watch. Presently, with something of the equable velocity of a bumble-bee, not very high above the stream, and faithfully tracking its windings, a bird scuds past, a bird wearing a very white waistcoat, and, seemingly,1 a very black coat. Perhaps, instead of this, we first catch sight of him perched on a stone, in mid-stream by preference, dropping a series of incessant curtseys to the universe at large; or, again, our first notification of his neighbourhood may be a tinkling silvery trill, heard through the rush of waters, something like the song of the wren, and, like that strain and the redbreast’s, gracing autumn as well as spring.
The bird thus recognisable is the water-ousel, otherwise the dipper, and if we pay a little attention to his movements, we shall have no difficulty in understanding how he comes by this other name. Though, as we have seen, he flies well, he obviously does not feed on the wing, and when in search of food he imitates in his manoeuvres none of the birds we are accustomed to see. He does not hop like the robin, and though he will run the length of the stone on which he is, he does not, like the wagtail, patter up and down the shore-line in quest of prey. Not the surface or edges of the stream, but the bottom, is his hunting-ground, and to it at no long intervals down he goes. Ever and anon, we can hardly mark how, he is gone from the stone where we saw him, disappearing in the water like a bubble that bursts or a may-fly sucked down by a trout.
Presently he is out again on the same stone or another, but the chances are that we discover him there, without being able to notice how he arrives, as though he had been shot into vision as he melted out of it. Sometimes from the wing he will plump into a tumbling stream, going down in it as if made of lead, and after a time he is on the surface as buoyant as a cork, and then sinks again without the apparent effort of a diving-bird, simply ducking his head and vanishing. At other times he works in shallow water with only his back above the surface, finding, as it seems, no difficulty in keeping himself submerged, raising his head and lowering it again to forage at the bottom, as he moves. How he performs these feats no one appears to know with certainty. But one thing is certain —the bird is not carried away with the stream, for he will work backwards and forwards, with perfect unconcern, across a tumbling rapid.
The nest is in keeping with the bird’s habits, being built hard by the waterside, on the face of a rock, on the pier of a bridge, under an arch, or even sometimes on a dry spot behind a waterfall, so that the parent bird has to go in and out, and the young catch their first glimpse of the world at large through a curtain of rushing water. The nest is domed, like that of the wren, and is most artistically assimilated to its surroundings, being likewise carefully felted to make it waterproof. The young, as befits their situations, long before they have left the nest understand that the water is their safest refuge, and how best to make use of it.
The water-ousel is thus stamped in the family of birds with an individuality not only notable but unique, uniting in his single self the most extraordinary contradictions—”a water-bird that sings, a song-bird that swims and dives”.2 For though in his habits more truly aquatic than a duck—though he lives above the waters, except when getting his living below them, though waters to please his taste must be turbulent and brawling, so that, turning his back on placid low-country streams, he elects to dwell on rivers that foam over rocks, and burns that leap from the sides of hills—yet, but for the fact that he is what he is, he has no right, that naturalists can discover, to be called a water-bird at all: none of the classifications which they can make will bring him into relationship with any birds but those that most distinctively belong to the land: no single feature of his structure would give a closet-naturalist any hint of the kind of life he leads. “The acutest observer,” says Darwin,3 “by examining the dead body would never have suspected its sub-aquatic habits.”
The dipper, in fact, according to Most naturalists,4 is a species of thrush, or a link between that family and the flycatchers. He has the feet of a thrush, with no trace of a web, the bill of a thrush, and the plumage of a thrush. Yet his foot never perches on a tree, and a minute’s immersion would reduce a thrush’s feathers to a condition of bedraggled uselessness.
Here, therefore, we have a problem presented to us of which account must be taken by any theory which deals with the origin of species. If the water-ousel be really a development from the same stock whence spring the thrush, the blackbird, and the fieldfare, what has been the agency which has availed to make him as unlike them all as one bird can be to another? For after all, it is not the frame of bones, muscles, and nerves that constitutes a creature’s essential character, but the mysterious force which energises through them. The dipper’s thrush-like features no more make him a thrush than likeness of face and gait showed Major Pendennis to be of the same stuff as the Duke of Wellington.
The problem is so notable that such a theory as the Darwinian must needs take account of it, and in studying that account we have an opportunity of studying in the best possible form—that is to say, in a concrete instance—the sort of explanation in which that theory deals.
Wallace thus handles the question:5
“Here then we have a bird, which, in its whole structure, shows a close affinity to the smaller typical perching birds, but which has departed from all its allies in its habits and mode of life, and has secured for itself a place in nature where it has few competitors and few enemies.
We may well suppose that, at some remote period, a bird which was perhaps the common and more generalized ancestor of most of our thrushes, warblers, wrens, etc., had spread widely over the great northern continent, and had given rise to numerous varieties adapted to special conditions of life. Among these some took to feeding on the borders of clear streams, picking out such larvae and molluscs as they could reach in shallow water.
When food became scarce they would attempt to pick them out of deeper and deeper water, and while doing this in cold weather many would become frozen and starved. But any which possessed denser and more hairy plumage than usual, which was able to keep out the water, would survive; and thus a race would be formed which would depend more and more on this kind of food.
Then, following up the frozen streams into the mountains, they would be able to live there during the winter; and as such places afforded them much protection from enemies and ample shelter for their nests and young, further adaptations would occur, till the wonderful power of diving and flying under water was acquired by a true land-bird.”
It may be well to remind ourselves that in the history thus sketched one fragment only is matter of fact, namely, that there are water-ousels. The rest is pure speculation based, not upon that fact, but upon an assumption as to how the fact came to be. “Well”, as Uncle Remus has it, “It might have been so but then, you see it mightn’t”. The construction of histories, such as we have heard proves only this—that by taking a great deal for granted we can imagine things to have proceeded in a certain way. But unless we have good reason to believe that we thoroughly understand the laws and constitutions of organic life, we can have no assurance that the process so imagined is even possible, and still less, if less can be, that it has actually occurred.
It seems very needful to remind ourselves of this, for apparently it is often assumed that, because we can thus in fancy bridge over a difficulty, the difficulty vanishes. But it is hard to see what scientific purpose such imaginative stories serve.
If we wish to know how an ousel dives, the only thing to do is to go and look; it would be worse than useless to consult instead our inner consciousness as Aelian or Pliny would have done, and then tell the world, as a contribution to its knowledge, how we think it likely that the operation is performed. And yet we know that dive he does, and that there must be some explanation of the operation.
With regard to his history, on the other hand, we know nothing, except that he exists; we do not know that there is any explanation of his development from a land-bird, because as yet we have not proved that he has so developed: and even if we know this, we could scarcely pretend, with any show of reason, to describe the complex process of his genealogical descent, when we know that we could not by a like method arrive at the truth concerning the mode of his descent into the water. It is, in fact, only where our ignorance is complete that we venture to amuse ourselves with such conjectures; the greater our knowledge the more we perceive their futility.
In the imaginary history, for example, given of the dipper, we do not even know that any of the factors ever existed which we employ in our calculation. We do not know that there ever was a “common generalised ancestor” from whom our perching birds are sprung. Even given that ancestor, we do not know by what several lines our existing species have descended from him, for naturalists cannot agree how to classify them.
Finally, granting this point again, in evidence for the possibility of all the various stages through which we trace the bird’s formation, we have nothing to quote but our own ignorance: we can say no more than this—that we see no difficulty in the way, while there may be ten thousand difficulties which we do not see. It would be cold comfort to the passenger on an express train rushing onward through a densely dark night, to be told by the driver that he could see no signals at all, and, therefore, was not aware of any portending danger; and in like manner we require from our scientific guides, if they are to inspire our confidence, not merely that they should perceive no obstacles, but that they should descry positive indications that the course is clear.
In contrast to all this speculation there is something very satisfying in the simple direct statement recorded in the first chapter of Genesis that God created every winged fowl after his kind. This has, we think, more credibility than the speculations of Wallace, or any other, for it has the whole Bible and much of the history of the world behind it. It has never been refuted.
References
- “Below the breast is a chestnut band, and the head and nape are chocolate brown; eacfi slate-grey feather is broadly edged with black on wings, tail, and back.” (C. M. Clark).
- Johns’ British Birds in their Haunts, 72.
- Origin of Species, 185 (5th Edition).
- Opinions differ on this, as is bound to be the case when so much is based on speculation. Whichever classification is adopted, the difficulties outlined by the author still remain.
- Darwinism, 117. Although this was written in 1889, the game of speculation is still played in an identical manner by the modern evolutionist.
We Spend too Much Time Ridiculing Evolution