in length inhabits the sides of lakes and the banks of

rivers in Australia and Tasmania.

2. The duck-bill is an essentially aquatic and burrowing animal, and is suitably

formed for its resi

dence in the water or under the earth. The fur is thick and soft, and is readily dried while the animal enjoys good health, but becomes wet and draggled when the creature is sick. The opening of the ears is small and can be closed at will, and the feet are furnished with large and

complete webs, extending beyond the claws in the fore limbs and to their base in the hind legs.

3. It can swim almost as rapidly as a fish, but is obliged frequently to come to the surface to breathe. The fore-feet are employed for digging as well as for swimming, and are therefore armed with powerful claws rather more than half an inch in length, and rounded at their extremities. With such force can these natural tools be used, that the duckbill has been seen to make a burrow two feet in length. through hard gravelly soil in the space of ten minutes. While digging, the animal employs its beak as well as its feet, and the webbed membrane contracts between the joints so as not to be seen.

4. The food of the duck-bill consists of worms, water insects, and little mollusks, which it gathers in its cheekpouches as long as it is engaged in its search for food, and then eats quietly when it rests from its labors. The teeth, if teeth they may be called, of this animal are very peculiar, consisting of four horny channeled plates, two in each jaw, which serve to crush the fragile shells and coverings of the animals on which it feeds. It seems seldom to feed during the day, or in the depth of night, preferring for that purpose the first dusk of evening or the dawn of morning. During the rest of the day it is generally asleep. While sleeping, it curls itself into a round ball, the tail shutting down over the head and serving to protect it.

5. The mode of nursing the young is very singular. It appears that the mother makes her young ones follow her into the water, and that she diffuses her milk around her; this liquid floats to the top of the water, and is immediately sucked up by her young. This manner of proceeding would suffice in itself alone to make the duck-bill one of the most astonishing of animals.

6. This creature seems to accommodate itself to bondage very badly. Mr. Bennett possessed two young ones, which he had captured in a burrow; and although he had not removed them from their native country, and had bestowed upon them the most assiduous attentions, he could not keep them alive: they died after five weeks of captivity. "They were," says Mr. Bennett, "very frolicsome little things, and played like kittens. They were very fond of dabbling about in a dish filled with water and furnished with a tuft of grass; they slept a great deal, especially during the day. Their food consisted of bread sopped in water, af hard boiled eggs, and meat chopped very fine."

69. THE STRUCTURE OF BIRDS.

ad-ap-ta'tion, fit arrangement.

con-triv'an-çes, devices.

in-fer', conclude, reason.

pro-pelled', driven forward.

1. LET us suppose that none of us had ever seen a bird, and that a traveler, who had been in distant countries,

came home and told us that he had there met with animals that did not swim through the water like fishes, nor walk

on the earth like dogs or horses, but soared far higher into the air than a boy's kite, and could move through it at the rate of forty, or sixty, or perhaps, a hundred miles an hour. How surprised we should all be at this wonderful story!

2. And if we believed the traveler, how eagerly would we listen to the description of animals, that instead of being clothed with scales like a fish, or hair like a cow, had the body covered with feathers; and instead of having two fore-legs, like our common animals, had the limbs of the forepart of the body of a different shape, and so contrived, that by their movements the creature was not only sustained in the air, but propelled rapidly forward!

3. If you had heard these wonderful facts for the first time, and were talking about these strange unknown animals, all would infer that they must be differently formed from beasts or fishes, and would try to imagine how they were made. Perhaps one might say, "Their bones must be very strong, for unless they were so, they could not take such long flights." But another might say, No; if their bones were very strong, they would be very heavy, and then the bird would not be able to fly at all; the bones, I think, should be very light."

4. Still another might say, "It would not be enough that they should be both strong and light at the same time, if that be possible, but the cords or muscles, by which the bones are moved, must be so made as to work with vigor and effect." But then a fourth might exclaim,

"All this would not be sufficient; for if I run for a quarter of a mile I am out of breath: how can birds go at so great a rate and for so long a time?"

5. These several points of inquiry can be answered only by actual examination of a bird. It will then be found

that the bones do combine the two qualities of lightness and strength. They do so, not only because of the material of which they are composed, but also because of the manner in which they are severally shaped and united.

6. The muscles, also, will be found to be so formed and so placed that they act with the greatest possible advantage; and with regard to the breathing, there is an adaptation expressly suited to the wants and habits of these creatures. The air from the wind-pipe passes not only into the lungs, but from them into cavities or air-cells, situated in different parts of the body. The blood is thus more freely exposed to the air than it is in other warm-blooded animals; the body is rendered more light and buoyant, and increased vigor is given to every part of the frame.

7. The air penetrates even into the bones, so that in birds of rapid or powerful flight, the hollow part in the center of the bone is filled, not with marrow, but with air. If an architect, accustomed, in planning his buildings, to calculate in what way he could shape his timbers so as to combine the greatest lightness with the greatest strength, were to examine the framework of the bones of a bird, he would find all his contrivances there surpassed.

8. The blood of birds is not cold, like that of a frog or a fish, but owing to their mode of breathing, is warmer than that of our common domestic animals. This heat would soon pass away from birds as they fly through the air or swim in the water, unless their bodies had some kind of covering to enable them to retain it. And accordingly they have a covering, which is, at the same time, light and It is as you well know formed of feathers, those next the body being shorter and finer, those outside larger, stronger, and tinted with a splendid variety of colors.

warm.

R. PATTERSON.