That the bones might not interfere with motion, they are provided with hinges or liga

ments.

That the ligaments might work smoothly into one another, the joints are separated by gristles or cartilages, and provided with a gland for the secretion of oil or mucus, which is constantly exuding into the joints.

478. There are 248 separate bones in the human body, classed under those of the head, the trunk, and the extremities.

The skull, or cranium, consists of eight pieces, and serves as a vault and protection to the brain, There are also the cheek-bones, the jaws, and 32 teeth imbedded in them.

The head is joined to the trunk by the vertebræ, consisting of several short bones, to the upper part of which it is fastened by a hingejoint, and turned in the socket of the next lower one by suitable muscles to the right or left.

479. In the front and centre of the trunk is the breast-bone, extending from the neck to the abdomen; and opposite to it, in the back, is the spine or back-bone, which extends from the skull to the bottom of the loins, and is a long chain of separate short bones, called vertebra.

These serve as the support of seven hoops or ribs, which are inserted in them, and form the chest or thorax, in which are the heart, lungs, &c.

Beneath them, inserted in the spine only, anc xtending but half way round the body, are tive

false ribs. The hip bones, with other bones st tached, supporting the abdomen, are called the pelvis.

480. From the neck to the top of each arm, & bone extends on each side, called the collar bone, and the blade-bones are independent sup porters of it. The bone extending from the shoulder to the elbow is called the humerus,

From the elbow to the wrist are two bones, the outer of which is the radius; the inner the ulna. The thigh-bone is called the femur; the knee, the patella; and the leg has two bones like the arm, the inner called the tibia, and the outer the fibula.

481. The Animal Frame is constantly exhausted and renewed; so that every particle of the human body is changed in the compass of a year!

Nor is it less surprising that so many different substances as compose every animal body, should also be secreted by the glands from the same blood, than that that blood may, in every instance, be traced to grass for its origin,

Obs,--Those functions by which aliment is assimilated for the nourishment of the body, are digestion, absorption, circulation, respiration, and secretion; and the effect of such assimilation is called nutrition.

2.--The food received into the stomach after mastication by the teeth, and bring mixed with salina, is con verted into chyme by the gastric juice, the chyme passes into the intestines, where it is converted into chyle and excrementitious matter; which last, being .eparated by means of bile, is evacuated from the body; whilst the chyle is absorbed by the lasteals and conveyed into the blood-vessels,

3.The absorbent system consists of the lacteals, lym phatics, the thoracic duct, and the glands called conglobate throughout the body.

4.-Glands are organic bodies consisting of blood ves sels, nerves, and absorbents, intended for the secretion or alteration of particular fluids. They are divided into four classes, simple, compound, conglobate, and conglomerate; the orifices of glands are said to be peculiarly

irritable.

5.-Secretion is the process by which various fluids are separated from the blood by means of the glands. The secretions are divided into the saline, as sweat and urine; the oleaginous as the fat, cerumen of the ear, &c.; the saponaceous, as bile and milk; the mucous, as on the surface of membranes, &c.

6. Sensibility is the faculty of perception by the contact of an extraneous body; and this principle is generally didused in our corporeal organs, but in different degrees. That modification of animal matter, in which sensation appears peculiarly to exist, is termed nervous.

7. Motion is effected by the muscular fibre contracting by volition; but the will can only exercise this power, through the medium of the nerves. Irritability is the power of contraction, inherent in our bodily organs, but not liable to be influenced by the will.

482. All the senses of animals, and all their varied powers of action, are exactly adapted to their different species of existence. What is food for oue, is poison to another; and every one finds provision according to its natural habits.

Every thing, also, is in exact proportion; and every provision of nature harmonizes with the corresponding desires and wants of animals. Nature's unnumber'd family, combine

In one beneficent, one vast design;
F'en from inanimates to breathing man,
An Heaven onceived an Heaven-erected plan;

Onward, from thuse, who shat of lowly dredy.
The wholesome equipoise through all to keep z
As faithful agents in earth, sea, and air,

The Lower World to watch with constant care: Her due proportion wisely to conserve t-A wondrous trust, from which they never swerve. PRATT's Imwer World 403. Linnæus divides Animated Nature into," 1. QUADRUPEDs (Mammalia), of which there are already known to man about 230 species. 2. BIRDS, of which there are about 1,000 species.

9. AMPHIBIOUS ANIMALS, of which there are about 100 species.

4. FISHES, of which there are about 500 species.

5. INSECTS, of which there are 2,000 species. And 6. WORMS, of which there are 800 species.

484. The first class of animated beings, called mammalia, comprehends all those that suckle their young: and have warm red blood flowing in their arteries.

Their bodies, for the most part, are covered with hair, in quantity proportioned to the cli mate they inhabit. Beneath this covering, is a skin of various thickness, inclosing a frame or skeleton of bones, acted upon by a system of muscles and tendons, which are put in motion by nerves communicating with the organ of sense and the will of the animal.

They have Blood, for Life; Bones, for Strength Muscles, for Motion; and Nerves, for Sensation.

485. Linnaeus divides mammalious animals, or those which suckle their young, into seven orders; which are chiefly regulated by the, aun ber and situation of the teeth.

a. Primates, or animals having two canine and four cutting teeth, and furnished with two pectoral teats. To this class belong man, the ape, the mançauco, and the bat.

b Bruta, or animals which have no cutting teeth in either jaw; as the elephant, the sloth, the ant-eater, &c.

c. Feræ, or animals whose cutting teeth vary from ten to two. This order includes most of the formidable rapacious quadrupeds; as the १. lion, the tiger, the bear, &c.

d. Glires, or animals which have only two cutting and no canine teeth; as the hare kind, the mouse, the squirrel, &c.

e. Pecora, or animals which are hoofed, and have no cutting teeth in the upper jaw, in cluding the camel, the deer, the sheep, the oxkind, &c.

f. Bellua, or quadrupeds with cutting teeth in each jaw, as the horse, the boar, &c.

Cete, or animals whose teeth greatly vary in different genera. This order comprehends all the whale tribes; which, from certain similarities of structure, are arranged under the class of quadrupeds.

486. Birds, the second class, constituting those covered with feathers, have two wings to fly with, a tail to direct their flight, and a hard bony bill. Their bones are hollow and light;