In vocabulary, comprehension, and arithmetic only a slight difference is found between the scores made by people in their thirties, the period when their abilities in these areas are highest, and the scores made by people 70 years old.

Many of the common sayings and beliefs about growing old have had to be revised in the light of new information that hasbeen developed by medical science in the last twenty years. We used to say that a man is as old as his arteries. Now we realize that changes in the arteries may go on without aging of all the rest of the body. A man is as old as his skin, his adrenal glands and his nervous system, even more than his arteries. Aging shows up most definitely in the skin and in the brain.

Just above the kidneys lie glands which in recent years have assumed so much significance that the knowledge concerning them has created a new era in medicine.

In most instances people pick out a child because he is dark or fair, fat or lean, because his hair is curly or straight, blond or brunette. The wise couple will realize from the first that the health of the child is much more important than the tilt or turnup of his nose.

An extremely cute baby may be just the opposite when he reaches eight years of age. The fat babies get thin and the thin ones get fat; the curly-headed blond six months of age may be a straight-haired raven at fifteen.

In girls this period begins at about twelve years of age and lasts ten years. In boys it begins at about fourteen years of age and lasts for a varying period, from seven to ten years. During this period. important changes take place in the body and mind of the child. These changes are the characteristics that distinguish the grown man or woman from the child. During the period of adolescence growth is more rapid than at any other time except during the first two years of life.

The child's school years coincide with the time when his health needs and his general life situation are fairly stable. Medically, he will be exposed to a variety ofcontagious diseases which he usually copes with easily. There is, of course, always the risk of such a major illness as rheumatic fever, but actually the school-age youngster is more frequently in danger from automobiles than from serious diseases.

In the throat and back of the nose lies a considerable amount of tissue which doctors call lymphoid tissue. Lymphoid tissue picks up infectious germs and helps the body to get rid of them. Occasionally, however, this tissue itself becomes infected and inflamed. The lymphoid tissue enlarges. Then it becomes more dangerous than helpful to the body and requires removal.

Above the kidneys lie two small bodies known as the adrenal glands. One portion of these glands secretes a substance now generally called adrenalin, which has the power of constricting the blood vessels and raising the blood pressure. Another portion of the glands, known as the cortex, which is the outer portion, secretes a different substance, generally called cortin.

This serious disease of men and animals is caused by fungus growths, which grow in extended chains. The actinomyces grows like a star. When the condition affects cattle it is called lumpy jaw. Cattle are attacked by the disease more frequently than men.

When a human being is affected with actinomycosis, it is usually from chewing grass or straw or grain which has been infected with the organisms. Therefore the condition is more frequently seen in laborers and farmers than in other classes of people.

When the anterior portion of the pituitary gland becomes excessive in its action, there is enlargement of the hands, feet, jaws, lips, nose, and tongue, to which the general name "acromegaly" is given. Closely related is gigantism, in which all the body is affected uniformly with overgrowth.