DIGESTIVE ORGANS. The digestive system comprises greater range of structure and diversity of function than any other system in the animal body. The pathological changes met with, therefore, differ widely at first glance. Essentially they are identical in all situations, the apparent differences depending on variation in prominence of the individual components. The mouth of an infant with "thrush" and the small intestine of an adult with typhoid fever show congestion, accumulations of leuco cytes, death and desquamation of superficial cells, oedema of subjacent tissues because both are the seats of inflammation caused by a micro-organism, however widely different they may appear to the eye. (See ALIMENTARY CANAL, DISEASES OF THE, and allied articles.)