The system of “lateral line” organs of fishes have at times been thought to be concerned with the chemical sense. This is probably not the case, although their exact function is a question still under dispute. In a general way, the taste buds, or sense organs of taste of fishes, resemble those of the human being. They are either flask- or cup-shaped, and are composed of two types of cells, called supporting cells and taste cells. The latter cells end peripherally in a hair or bristle, just as the same kind of cell in the human taste bud. _Land-Dwelling Animals_ There seems to be no experimental evidence for a specific sense of taste in amphibia, or reptiles. But sense organ structures have been described upon the tongue and soft palate of the frog, where they are said to occur in hundreds. They are disc-shaped structures, made up of several kinds of cells, which correspond to the real taste cells and supporting cells of the human sense organ. The taste cells end peripherally in several hairs or bristles, and at their central end make connection with nerve fibers. In the reptile group there is neither experimental evidence of taste sensitivity nor anatomical evidence of the presence of taste corpuscles on the tongue or in the mouth cavity. The experimental evidence for the taste sense in birds is slight. It certainly is greatly overshadowed by the keen senses of sight and hearing. Birds seem to represent one case, however, in which taste is more important than smell. Taste sensitivity for different chemical substances, in the case of young chickens, at least, seems clear from certain studies of instinct and learning, in which they accept certain kinds of food and reject others after tasting them. In considering the sense of taste in birds it must be remembered that most of them swallow their food without chewing it or without having it reduced to liquid form through mixture with saliva. The tongue, which varies in character considerably in different types of birds, is in most cases covered with a horny coat. Numerous hard papillæ are found upon its surface. Microscopical examination of these papillæ shows nothing which can correspond to taste buds or to gustatory cells. The parrot is said to form an exception to most birds, in that it has a relatively soft and fleshy tongue, with numerous papillæ, and also in that it chews its food. In the duck, which has a large tongue, there are certain portions which lack the hard covering common to birds’ tongues. Here, in addition to a large number of tactile corpuscles, there are groups of cells which resemble somewhat true taste corpuscles. The peripheral ends of their cells reach the surface of the mucous covering of the tongue. The cells do not end in the bristle, or hair-like, formation, as those of the human taste cells, but in a pointed elongation of the protoplasm. Experimental evidence of the function of these structures is lacking.