erable distances, as does the shark, but with different motives.

GENERAL ECONOMY.

Why are mammiferous animals the most useful to man? Because of the difference in their forms, their great docility and their strength. From no other class of animals has man been able to obtain such faithful, serviceable, and valuable assistants; no others are so indispensable to him for his immediate use and support. Whole nations are enabled to supply nearly all their most urgent necessities with a single species of mammiferous animals: -- the Greenlanders, with the seal; the Laplanders, Tunguses, &c, with the rein-deer; the Aleutians with the whale.

The various uses of mammiferous animals to man, may be classed as follows:- for riding, draught, husbandry, carrying burdens - the horse, mule, ass, ox, buffalo, rein-deer, elephant, camel, llama, dog. For hunting and watching the dog. For destroying mice and other vermin- the cat, hedgehog, anteater. For food - the flesh of oxen, the sheep, goat, swine, the deer genus, hare, rabbit, besides lard, tallow, blood, milk, butter and cheese. For covering and clothing, furs, leather, hair, wool. For fuel and burning-tallow, train-oil, spermaceti. For writing, bookbinding, &c,- parchment, leather. For other miscellaneous uses-bristles, hair, antlers, horns, hoofs, ivory, teeth, bone, whalebone, bladders. For glue-guts, tendons, and bones. For strings-guts, (cat gut). Blood for Prussian blue and other colours. Bones and hoofs for ivory black, &c. Fat and marrow for soap. Excrement for manure, fuel, sal ammoniac, &c. Lastly, for medicines-musk, castor, hartshorn, milk, and other articles. -- Blumenbach.

Why may several animals of this kind be also said to be directly or indirectly injurious to man?

Because many carnivorous animals, particularly of

PART II.

6*

the cat tribe, attack him. These, and many others, as the weasel, marten, polecat, glutton, otter, and whale, destroy serviceable animals, or injure trees, plants, fruit, corn, &c, as the field-mouse, hamster, lemming, deer, hare, beaver, monkey, elephant, rhinoceros, hippopotamus:- -or consume our provisions as the rat, mouse, and bat. No animal of this class appears to be venomous when in a state of health, except, perhaps, the male of the duck-billed animal, (ornithorincus) the spur on the hinder leg of which is considered poisonous. Blumenbach.

Why are the skins of animals steeped in the infusions of certain barks for forming leather?

Because the skins being previously prepared by soaking in lime-water, which renders the cuticle and hair easily separable, and afterwards softened by allowing them to enter into a degree of putrefaction,

-the action of infusion of oak-bark, or other astringent vegetable matter, is increased until a complete combination has taken place, which is known by the leather being of an uniform brown colour. throughout; whereas, in imperfectly tanned leather a white streak is perceptible in the centre. Brande. - Such is the process of tanning.

Why is leather curried with oil while moist?

Because, as the humidity evaporates, the oil penetrates into the pores of the skin, giving it a peculiar suppleness, and making it, to a considerable extent, water-proof. As familiar examples of this and the preceding processes, the thick sole-leather for shoes and boots is tanned; the upper leather is tanned and curried. Aikin.

Why is it commonly supposed that the flesh of young animals contains more gelatine than that of old ones? Because the young flesh is merely more soluble and more easily extracted by boiling.

Why, in making animal jelly, is simmering preferable to boiling?

Because, by boiling, the albumen is so firmly coagulated as to envelope the gelatine and protect it from the solvent power of water; whereas, simmer-. ing at a temperature from 100 to 120 removes from the muscle the whole of the jelly. - Brande.

Why have all animals more or less fat?

Because it may serve as a store of nourishment; being most abundant, when the animal is well furnished with a copious supply of food, and gradually diminishing in quantity as the food becomes scarcer, and disappearing when, from want, a lingering death has been produced.-Fleming's Zoology.

Why is it necessary to vary the food of animals? Because the stomach, like other organs, can be excited to the due performance of its functions only by supplying it with an appropriate stimulus. The same alimentary substance long continued probably loses its stimulating power, and thus, though it abound with nutritive properties, the stomach is incapable of acting upon it.

Why does the blood of different animals vary in smell? Because the blood of each species contains a principle peculiar to each, which is very volatile, and has an odour resembling the sweat or exhalations of the animal. This principle may be separated by a very simple process; when it will appear that the blood of the ox has a strong odour of the perspiration of the horse; that of the sheep, a strong odour of wool, impregnated with the perspiration of that animal; that of the dog, the odour of the transpiration of a dog, that of a pig, the disagreeable odour of a piggery; that of a rat, the bad odour belonging to a rat. From the French of M. Barual.

* Put a few drops of blood into a glass, to which add one-third or half as much concentrated sulphuric acid, and stir the whole together with a tube, when the odoriferous principle will be exhaled.

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Why are there great changes in animals on their introduction into a new country?

Because every animal appears, like man, to require time to accustom itself to climate. Thus, in America the hog multiplies very rapidly, and assumes much of the character of the wild boar. Cows did not at first thrive, but in St Domingo, only twentyseven years after its first discovery, 4,000 in a herd was not uncommon. Cows never thrive nor multiply where salt is wanting either in the plants or in the water. They give less milk in America, and do not give milk at all if the calves be taken from them. Among horses the colts have all the amble as those in Europe have the trot: this is probably an hereditary effect, Bright chestnut is the prevailing colour among the horses, The lambs which are not from merinos, at first are covered with wool, and when this is timely shorn it grows again; if the proper time is allowed to elapse, the wool falls off, and is succeeded by short, shining, close hair, like that of the goat in the same climate.

Why is it concluded that no large species of animals remains to be discovered in America?

Because there is no good reason assignable why any such should exist in that country, with which we are acquainted; and in fact, none have been discovered there during the last 150 years.

Why are not the bones uniform in shape?

Because each bone is not, as a mere pillar, intended to bear a perpendicular weight; but, according to its place, bears up against the various forces which are applied to it; and is expanded at the head to give a greater, and consequently a more secure surface for the joint, while its form regulates the direction in which the joint is to move. Archdeacon Paley has, with great propriety, instanced the form of the ends of bones, as proving design in the mechanism of a joint.

Why do certain animals change colour?

Thus,

Because of the effects of age and climate. the seal changes colour with his age. Many also become either gray, as the squirrel, or snow-white, as the ermine; with us, merely during the depth of winter, but in the north, throughout the whole. – Blumenbach.

Why have ruminating animals a four-fold stomach? Because its remarkable structure and mechanism may assist the rumination of their food. Thus the food, when first swallowed, and in a half crude state, is received into the immense first stomach, as into a storehouse in which it is only a little softened. From it small portions of food are successively taken up by the second stomach, which appears merely an appendage to the first, and propelled a second time through the gullet into the mouth. Next, the food, after being again chewed, is carried by a particular groove direct from the gullet into the third stomach, without passing through the two first; lastly, it is transmitted to be completely digested in the fourth, which approaches most closely to the stomach of other mammiferous animals.

DOMESTICATION.

Why does domestication produce certain variations in animals?

Because of the degrees of slavery and subjection under which those animals are to man. They do not proceed in half-domesticated species. In the cat, for example, a softer or harsher fur, more brilliant or more varied colours, greater or less size —~ these form the whole extent of the varieties in the species: the skeleton of the cat of Angora differs in no regular or constant circumstances from the wild cat of Europe.

Why are the most remarkable variations produced in the dog?

Because that animal is most completely under the