This sympathy is sometimes singularly manifest even in disease. In some cases of affection of the mesenteric glands, for example, where stomachic digestion remains for a time pretty healthy, and the general system suffers chiefly from the want of nourishment caused by the passage of the chyle into the blood being obstructed, the appetite continues as keen and often keener than before; because the system, being in want of nourishment, and the stomach healthy, all its natural causes continue to act as before; and accordingly, when food is taken, it is digested there as usual, but the chyle which is formed from it in the intestine can no longer be transmitted through the swollen glands in its usual healthy manner, to be converted into nutritive blood in the lungs; and the system thus failing to receive the required supply, recommences its cravings almost as soon as if no food had been obtained. When the disease has advanced a certain length, however, fever springs up, and destroys both appetite and digestion. The effects of exercise, also, shew very clearly the connexion between appetite and the state of the system. If we merely saunter out for a given time every day, without being actively enough engaged to quicken the circulation and induce increased exhalation from the skin and lungs, we come in with scarcely any change of feeling or condition; whereas, if we exert ourselves sufficiently to give a general impetus to the circulation, and bring out moderate perspiration, but without inducing fatigue, we feel a lightness and energy of a very pleasurable description, and generally accompanied by a strong desire for food. Hence the keen relish with which the fox-hunter sits down to table after a successful chase. This intimate communion between the state of the system and that of the stomach is a beautiful provision of Nature, and is one of the causes of the ready sympathy which has often been remarked as existing between the stomach and all the other organs--in other words, of the readiness with which they accompany it in its departure from health, and the corresponding aptitude of _their_ disorders to produce derangement of the digestive function. Apparently for the purpose, among others, of thus intimately connecting the stomach with the rest of the system, it is supplied with a profusion of nervous filaments of every kind, which form a closely-interwoven nervous network in its immediate neighbourhood, and the abundance of which accounts for the severe and often suddenly fatal result of a heavy blow on the pit of the stomach.