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BIRD. 



articulations of the foot and leg, are the chief points 

 which render the foot either a good walking one or 

 not. If these joints have these motions only in the 

 vertical plane and parallel to the mesial plane of the 

 body, without any lateral flexure, then the bird will 

 walk firmly; and whether its march shall be quick or 

 slow upon one kind of surface or another is made out 

 by the details, the relative length of the member, and 

 the form and magnitude of the toes and claws. If a 

 man has his knees or his ankle-joints with lateral play, 

 or with a twist inward at the knees, or more espe- 

 cially with a twist either way at the ankles, he walks 

 never a bit the better though his feet may happen to 

 be, as is often the case with inward-twisted ankles, 

 as broad as shovels. It is also impossible even to 

 imagine members more finely organised for their 

 proper use than the toes of long-armed apes and spi- 

 der monkeys ; and yet, from the twist of the ankle, 

 which is an outward twist, or one which turns the sole 

 of the foot inwards, they walk not only with great 

 awkwardness but with great pain. 



The articulation of the toes of a bird, answers in 

 anatomical arrangement to the ball joints of the toes 

 in man ; but in the act of walking it answers to the 

 ankle-joint. If this joint is firm, and the joints above 

 it so articulated as that the weight of the bird comes 

 perpendicularly upon its centre, then the step of the 

 bird will be firm ; but if this joint is loose, or even if 

 the strain takes it in an oblique direction, the bird 

 will wriggle or waddle, and waste in rolling from side 

 to side great part of that muscular exertion which 

 would carry a better set bird straight forward on its 

 way. The woodpecker is straight and firm on these 

 articulations ; and even its capacity of holding-on 

 upon the trees, requires that it should be so. It is 

 not, as we have seen, a clutching climber, which holds 

 on by grasping with the foot, for even when the 

 woodpecker perches upon a branch for repose, it does 

 not perch across, as most perching birds do, but length- 

 ways, or with the axis ot its body parallel to that of 

 the branch, it holds on by a combination of mecha- 

 nical resistances, acting all in the same plane, though 

 in different directions; and therefore any lateral 

 motion in the joints of the foot or leg would turn that 

 foot into an instrument of positive instablity a crow- 

 bar to wrench the bird from the tree. 



But when we consider the style in which the parrot 

 climbs, we can easily perceive that that looseness and 

 twist, of the articulation of the toes especially, which 

 make it so bad a walker, are the very best for its pro- 

 per habit. It is the same with the twisted-limbed 

 mammalia to which allusion has been made for illus- 

 tration ; they could not have performed their part in 

 the system of nature, unless they had had that very 

 formation which makes them appear so awkward 

 when out of their proper sphere. When we come to 

 notice the feet of the water-birds, we shall find 

 instances of structure differing from each other to the 

 same extent, and nearly in the same manner as these 

 differ ; and if it lay within our province, we could 

 easily show the very same differences of adaptation 

 and use, and the same perfect accordance of the one 

 with the other in all animals endowed with locomo- 

 tion, whether vertebrated or invertebrated, and whe- 

 ther of the magnitude of whales or the minuteness of 

 animalculi. Throughout the whole there is the most 

 complete evidence of mechanical perfection, always 

 competent to effect its purpose without supplemental 

 aid. And among most of those cases, probably 



indeed in every case of an articulated animal, whether 

 articulated internally in the skeleton, or externally in 

 the crust, where it has been supposed that suckers 

 and cements and other clumsy contrivances have oeen 

 resorted to in order to enable the animal to keep its 

 hold, a very few simple claws, or elastic pads, applied 

 with nature's mechanical skill, are not only all that 

 exist, but all that is necessary, and that more would 

 be an absolute incumbrance. 



Those attempts at explanation by such supple- 

 mental aids as have been alluded to, are found in 

 numbers in very many of the books (even those of no 

 measured pretence) which profess to treat of the 

 mechanics of the living world. But the accounts of 

 such structures always point out the origin of the 

 structure : it is a bungle ; therefore it is the work of 

 man : were it the work of God, it would be perfect 

 in its single and simple organisation, and more, even 

 could it be added, would overload and weaken it, just 

 as a machine of human invention is overloaded and 

 weakened when it consists of too many parts. That 

 joiner is a bungler in his art who must upon all occa- 

 sions use the glue-pot ; and that is the most perfect 

 piece of carpentry which stands firm without glue or 

 nail or any other supplemental fastening ; and when 

 we come to nature we find no such fastenings ; the 

 parts themselves have the requisite form, the requisite 

 adherence to each other, and the whole, by means of 

 its own organisation, has the necessary adhesion to 

 whatever kind of surface is to support the animal in 

 its ordinary motions. 



And here, as the subject presents itself naturally in 

 consequence of the explanations which have been 

 given of these feet, we cannot resist calling the atten- 

 tion of such readers as may not generally be in the 

 habit of attending to such subjects, to the very wide 

 and wonderful field for mechanical study which the 

 animal creation presents. Yet ample and apparently 

 exhaustless as it is, it is all acquireable knowledge, as 

 far as the telescope can survey in the one direction, 

 and the microscope in the other. 



The organisations of animals do not partake of the 

 unseen and therefore the mysterious nature of that 

 energy of life by which they are evolved and put in 

 motion. They are, in all their parts, wholly material, 

 and every motion, and every position of rest, of which 

 they are capable, admits of as certain explanation 

 an explanation as simple, if we would go the right 

 way to it, as the putting of a common balance in 

 equilibrio, by placing equal weights in both scales. 

 A leech may proceed by suckers, but no animal pro- 

 ceeds thus, unless its principal action in motion is a 

 lengthening and shortening of the body ; and when 

 we say of a swift-footed animal, that it must pause at 

 every step, and either fasten its foot by glue, or by 

 pumping out the air from under it, we afford a very- 

 certain proof, not only that we are imperfect in the 

 knowledge of nature's mechanics, but tnat we do not 

 understand the meaning and application of those 

 common laws of mechanics, which are set down in the 

 books, although we may be able to parrot the enun- 

 ciations. When we do not understand by what 

 means, or in what manner, an animal, or a particular 

 organ of an animal, which is new to us, and, philoso- 

 phically speaking, everything which we do not under- 

 stand is new to us, though we should have been in 

 the habit of seeing it daily for the longest life when 

 we do not thus understand, the most candid, and by 

 far the wisest plan, is to say so, because all mankind 



