Beneath the skin, underneath each ear, just behind the jaw, is a soft body, which ordinarily you cannot feel, but which, when inflamed by what is called “the mumps,” swells up into a great lump. In a sheep’s head you would find just the same body, and if you were to examine it you would notice fastened to it a fleshy cord running underneath the skin across the cheek towards the mouth. By cutting the cord across you would discover that what seemed a cord was in reality a narrow tube coming from the soft body we are speaking of and opening into the mouth. Just close to the soft body this tube divides into two smaller tubes, these divide again into still smaller ones, or give off small branches; all these once more divide and branch like the boughs of a tiny tree; and so they go on branching and dividing, getting smaller and smaller, until they end in fine tubes with blind swollen ends. All the tubes, great and small, are lined with epithelium and wrapped round with blood-vessels, and being packed close together with connective tissue, make up the soft body we are speaking of. This body is in fact a =gland=, and is called a =salivary gland=; as you see it is not a simple gland like a sweat gland, but is made up of a host of tube-like glands all joined together, and hence is called a =compound gland=. Being placed far away from the mouth, it has to be connected with the cavity of the mouth by a long tube, which is called its =duct=. You cannot fail to notice how like such a gland is, in its structure, to a lung. The lung is in fact a gland secreting carbonic acid: and the duct of the two lungs is called the trachea. The salivary gland beneath the ear is called the =parotid gland=; there is another very similar one underneath the corner of the jaw on either side, called the =submaxillary gland=. By each of them a watery fluid is secreted, which, flowing along their ducts into the mouth and being there mixed with the moisture secreted by the other glands in the mouth, is called =saliva=. In the cavity of the abdomen lying just below the stomach is a much larger but altogether similar compound gland called =the pancreas=, which pours its secretion called =pancreatic juice= into the alimentary canal just where the small intestine begins (Fig. 17, _g._) That large organ the liver, though the plan of its construction is not quite the same as that of the pancreas or salivary glands, as you will by and by learn, is nevertheless a huge gland, secreting from the blood capillaries into which the portal vein (see p. 62) breaks up, a fluid called =bile= or =gall=, which by a duct, the =gall duct=, is poured into the top of the intestine (Fig. 17, _e_). When bile is not wanted, as when we are fasting, it turns off by a side passage from the duct into the gall-bladder (Fig. 17, _f_), to be stored up there till needed. =49.= What are the uses of all these juices and secretions? To dissolve the food we eat.