pose, running down the back, but it is composed of twenty-four pieces of bone. Each of these pieces is called a vertebra. These are joined by a soft elastic— which means, when anything is bent or stretched, and the force which was used is removed, returns to its first shape-substance, called cartilage, which enables us to bend our back. These vertebræ are hollow, and contain the spinal nerve or marrow, and serve as a pillar or column for the support of our bodies. They increase in size from the neck down. When a person breaks his back, as it is usually called, these cartilages are broken, which can never be joined again. When the spine is diseased, the person rarely enjoys health afterward.

31. As people become older they are shorter; and men who stand and write for any length of time also become shorter, because the ligaments of the spine press down upon each other. The skull is united to the upper vertebræ by means of a joint.

32. Here we see what a wise provision is made for our ease and motion; for if our spines had been attached to our heads, so that we could not move them, how stiff would have been our bodies; and had our limbs also been firmly joined, we should have fallen every step we moved; but we have what is called the hinge-joint, to enable us to move the head upward and downward, and what is called the ball-and-socket-joint, by means of which we can turn our head in every direction, and enjoy much more than if it was arranged otherwise.

30. Of what is the spine composed? What is a vertebra? How are the vertebræ joined? What do the vertebræ contain? What do we mean when we say the back is broken? Do persons recover from a disease of the spine? 31. Why do people become shorter who stand for any length of time? How is the skull united to the upper vertebræ ? 32. What advantage are the hinge-joint and the ball-and-socket joints?

33. In all the joints, the ends of the bones whic. work together are tipped with gristle, that they may move easily. The spinal marrow passes through the spine, and if this be once broken, the limbs below would become numb and motionless, and life would soon end. There is an innumerable number of nerves passing from this spinal cord to the stomach, to the heart, the liver, and to every part of the body.

Joined to the spine b, b, are twelve ribs on each side, seven of which are united to the sternum or breast-bone a in front, that is composed of three small pieces of bone, which, although distinct at first, finally unite together, making one bone. These are called the true ribs then

33. With what are the bones tipped, and why? What takes place if the spinal marrow is injured or broken? How is the spinal marrow connected with the stomach, heart, and lungs, etc.? How many ribs are there? Describe the sternum? What are the true ribs ?

there are five which unite with the breast-bone by means of soft cartilages.

34. The collar-bone and shoulder-blade are also united to the breast-bone, and serve their purpose, the one forming the neck, the other the shoulder. The ribs are very important bones, for they enclose all those organs which give us life, and sustain it, as the lungs, heart, etc. So important are they, that we should be careful not to draw our clothing so tight around them that they will press upon these organs, for the ribs are softer than the teeth, and have also that substance called ligament-the same as in different parts of the spine-at the end, and they yield to any pressure upon them which sometimes causes death.

35. In a great many instances, where persons have been supposed to die with consumption, on examining their bodies after death, it was found that they had pressed their ribs so closely together that they had not power to breathe. In one instance which I have known, the lower ribs were closed over each other, so that the stomach could not digest the food, nor the heart circulate the blood, nor the lungs take in air. The action of all the internal organs was interrupted, which caused death.

36. We find a great many joints in the body, and in those situations where they are most needed. The arm is joined to the shoulder-blade in such a way that it can turn around; at the elbow there is a hinge-joint, to move

34. For what purpose are the collar-bone and the shoulder-blade? Why are the ribs important bones? What care should we take of them? 35. Is death ever caused by pressure on the ribs? Explain why this is the case. 36. Is there any system in the arrangement of the joints? What difference is there between the one at the shoulder and at the elbow ?

it upward and downward. Some have supposed that the hinge on the door was first thought of by seeing it at the elbow. Then we find another at the wrist, also

in all the fingers. There are twenty-seven bones in the hand and wrist. We might have had hands to move, made of only one solid piece of bone.

37. In this way we could not have used them for one half or three-quarters of the purposes we now can. We could not write to our friends; we could not raise our food to our mouths; the mechanic could not use his tools, however perfect they were; the lady could not play on her piano; the mother could not knit her stockings; the little girl could not sew and make her dollbaby's dresses; the little boy could not make his kite. nor spin his top, nor play with his marbles.

38. Every one would immediately say how inconvenient this would be. There is one man without arms who can do almost anything he undertakes; yet there is not another one to be found in the United States, or in the whole world. We could not move our limbs, our feet, or our toes, without joints. Think how awkward all our movements would be if our limbs were immovable, or were composed of solid bone. We should be confined to one spot, and could not walk or move.

39. What a world this would be, if its people were jointless, and what a blessed thing it is that we are furnished with these instruments! Man is the only

36. Is there anything in a house that resembles the hinge-joint at the elbow? How many bones are there in the hand and wrist? 37. What advantages arise from the great number of these bones? 38. Is there any instance where the other limbs have been substituted for the hands? What would be the consequence if we were jointless? 39. What dis tinction is there between man and other animals? What places man above monkeys?

animal that has hands, though the forefeet of monkeys resemble our hands, as they have nails like those on our fingers, and they can also use their feet very handily; but they have no intellect.

The foot is also remarkably constructed with its twenty-six little bones, connected with little joints, so that we can move very easily. If we look on the sole or bottom of the foot, we shall see that the middle of it appears as if arched or cut out. This enables us to walk more easily and gracefully, to run, skip, and jump, and to perform every motion we wish.

40. On examining the feet of different animals, we find that they are fitted or adapted to their peculiar wants and necessities, and to their character, food, and manner of life. The feet of apes and monkeys are constructed so as to enable them to climb trees; and in their native state, they live among the trees, and are continually climbing and hanging on the branches.

41. The mole lives in the earth, builds her house under the ground, and rears her young there; and they can dig through grass, and even hard gravelly earth, with their feet. The fore-feet of the goat, sheep, ox, and camel, have hoofs, which are double; but they have the appearance of a single one cut in two, and are called cloven. The camel has large, and what we should term, homely feet, but these are to support and move a large and unwieldy body, and to travel over the deserts of sand.

39. How many bones has the foot? How are they connected? Is there any peculiar arrangement to the sole of the foot? What advantage is it? 40. To what are the feet of different animals adapted? How are the feet of monkeys and apes constructed? 41. How does the mole use her feet? What can you say of the fore-feet of goats and sheep Describe the feet of the camel. How are they adapted to his wants?