Adenoids. If colds are neglected and allowed to run on, the inflammation spreads through the nose back into the upper part of the throat, or pharynx. Here it attacks a spongy group of glands, like a third tonsil, which swells up until it almost blocks up the nose and makes you breathe through your mouth. These swollen glands are called adenoids, and cause not only mouth-breathing, but deafness, loss of appetite, indigestion, headache, and a stupid, tired condition; so that children that are _mouth-breathers_ are often two or more grades behind in school, poor students, and even stunted and undersized. You can often tell them at sight by their open mouths and vacant, stupid look. A very simple and harmless scraping operation will remove these adenoids entirely, and what a wonderful improvement the mouth-breather will make! He will often catch up two grades, and gain two inches in height and ten pounds in weight within a year. [Illustration: MOUTH-BREATHERS Note how swollen the face is under the eyes and how tired and dull the whole expression.] Adenoids not only cause deafness by blocking up the tube (_Eustachian_) that runs from the throat to the ear,--the tube through which the air passes when your ear "goes pop,"--but are also the commonest cause of ear-ache and gatherings in the ear, which may burst the drum. THE TONGUE The Tongue is not Used chiefly for Tasting. If you will notice the next time that you have a bad cold, you will find that you have almost lost your sense of taste, as well as of smell, so that everything tastes "flat" to you. This illustrates what scientists have known for a long time, but which seems very hard to believe, that two-thirds of what we call taste is really smell. If you carefully block up your nostrils with cotton or wax, so that no air can possibly reach the smell region at the top of them, and blindfold your eyes, and have some one cut a raw potato, an apple, and a raw onion into little pieces of the same size and shape, and put them into your mouth one after the other, you will find that it is difficult to tell which is which. The only tastes that are really perceived in the mouth are bitter, sweet, sour, and salty; and even these are perceived quite as much by the roof and back of the mouth, especially the soft palate, as they are by the tongue. All the delicate flavors of our food, such as those of coffee or of roast meat or of freshly baked bread, are really smells. The tongue, which is usually described as the organ of taste, is really a sort of fingerless hand grown up from the floor of the mouth--to help suck in or lap up water or milk, push the food in between the teeth for chewing, and, when it has been chewed, roll it into a ball and push it backward down the throat. It is not even the chief organ of speech; for people who have had their tongues removed on account of cancer, or some other disease, can talk fairly well, although not so clearly as with the whole tongue.