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449 



along with not a very graceful motion. Besides, 

 though geese in their domesticated state are not much 

 in the habit of flying, they are birds of long-continued 

 and moderately rapid flight when in a state of nature. 

 From this combination of feet and wings, and adap- 

 tation of the feet both to walking and to swimming, 

 these birds have their muscles distributed over the 

 body much in the same way as common poultry, and 

 thus neither their feet nor their wings are very 

 remarkably characteristic. The foot is a swimming 

 foot of the simplest kind, and may be understood 

 from the annexed figure. 



Common Goose. 



Al! merely swimming birds, which float along with 

 part of the body above water, have the motion of the 

 feet more nearly in the vertical plane than the divers. 

 But there is, even in them, a very beautiful action of 

 the foot, brought about by the mere bending of the 

 leg, without any additional exertion of muscular 

 power. The moment that they begin to draw it for- 

 ward, after it has made the stroke, it begins to con- 

 tract, by the bending of the tarsal joint pulling the 

 tendon. The surface which the foot presents to the 

 water in the direction toward which it is pulled, is 

 thus not only constantly diminishing, but it is convex 

 in its form, and yielding as the joints are relaxed, so 

 that it " comes home" through the water with very 

 little effort on the part of the bird. When, however, 

 it begins to act in the taking of the stroke, it presents 

 the concave side, and that side keeps enlarging till, 

 at the time when the stroke is given, it has attained 

 its greatest breadth. It then comes to nearly a 

 horizontal position of the feet, and from this it is 

 drawn forwards with not much more breadth than 

 the edge to the water. 



This foot is exactly a paddle, only it acts better 

 both on the stroke and the return than any paddle 

 which man can construct. No doubt the paddle 

 which man uses is recovered through the air, and 

 thus the resistance of the water is wholly avoided 

 during that part of the operation. But still the exer- 

 tion which has to be made in raising the paddle is 

 much greater in proportion to the effect produced 

 than that made by the foot. 



The swan, though nearly or altogether equal to the 

 goose in flight, is much less upon land in its ordinary 

 habit, and it is accordingly better adapted for swim- 

 ming, and, as a necessary consequence, a worse walker. 

 Swans, indeed, stand in much the same relation to 



NAT. HIST. VOL, 1. 



goese (taking them on the average^) as the diving 

 ducks do to the swimming cues. Their tarsi are 

 shorter, the webs of their feet larger in proportion, 

 and the joints have rather more oblique motion. As 

 neither dive, the comparison of them is of course 

 made as surface swimmers ; and the attitude of the 

 swan upon the water has been a favourite theme with 

 poets and picturesque describers in all ages : and 

 the bird is stately as well as graceful, both when it 

 moves with closed wings and smooth plumage against 

 the breeze, and when it hoists sail, and takes the 

 wind in its raised wings, to aid or relieve the labour 

 of its feet. From its beauty, its size, and its tame- 

 ness, the swan is the best subject in which to study or 

 observe the action of surface swimming. All its evo 

 lutions upon the water are worthy of notice, and its 

 style of doubling and of backing is particularly so. 



All those surface swimmings in which there U 

 smooth motion are of course made with the alternate 

 foot ; for, as the feet are considerably in the rear of 

 the centre of gravity, if the bird was to attempt leap- 

 ing on both without something to hold on, the hiiidei 

 part would be jerked out of the water, and the fore 

 part plunged into it, by which means the progress 

 would become both unseemly and fatiguing. When 

 alarm, or any other cause, impels these birds to more 

 rapid motion along the water than they can accom- 

 plish with the ordinary swimming motion at its full 

 stretch, they take to the wing, and if they do not get 

 so high as merely to tip the water with their feet,' as 

 the skimming birds do, they make the same flutter, 

 and generally utter painful cries, as barn-door fowls 

 do when forced to the wing. 



The swimming ducks are less upon the water than 

 swans, as a considerable part of their food is found 

 on land, and they are incapable of reaching the bot- 

 tom in so deep water. Their bodies are also not 

 quite so well trimmed to the action of the swimming 

 feet, and they labour and wriggle more both laterally 

 and vertically, so that, though they can float about 

 for a considerable time, they are much sooner tired 

 when they attempt to swim upon a stretch. These 

 docks have the tarsi longer, the toes shorter, and the 

 action of the foot in swimming not so much to the 

 rear. The sheldrake is the most landward ; but the 

 foot of the common duck is perhaps very nearly the 

 average. 



Feet of the swimming arid the divii)g Ducks. 



The diving ducks are bad walkers, and seldom 

 upon land ; but they are more compact in the build 

 of their bodies than the swimmers. When, however, 

 we speak of swimmers and divers as contrasted with 

 each other, we must bear in mind that there is no 

 definite species with which the one ends or the other 

 NN 



