The hemispherical, or simple, papillæ are found distributed over the whole tongue surface and form in many cases secondary papillæ upon the larger fungiform and circumvallate type. The papillæ of these different types contain the largest number of the sensory ends of taste, or the taste bodies. These structures will be discussed in detail later. They are most numerous in the circumvallate papillæ, where one may find hundreds imbedded in the side walls of one papilla. They are also found in the side walls of the depression from which the papilla rises. The fungiform type also contain these taste bodies imbedded in their side walls, although there are some in which none have been discovered. According to Nagel, the taste bodies have never been found in the filiform type. He ventures the opinion that the taste bodies are not necessary to produce taste sensations, with the result that the filiform papillæ may, after all, have something to do with taste sensations. There is always the possibility, first suggested about 1870, that the free nerve endings in the tongue surface may give rise to taste sensations. _The Determination of the Taste Areas_ How shall the limits of the taste mechanism be determined? Two methods have been employed, and usually in conjunction. The first, or the anatomical method, consists in searching for the taste bodies (to be described later), and when they are found, to assume the possibility of taste sensations from the stimulation of that region. The second, or the physiological method, consists in applying stimuli of various sorts to different regions and finding whether taste sensations result. The limits of the taste mechanism, when determined by these two methods taken separately, do not always agree. But there are cases in which only one or the other method taken alone can be applied. For instance, in the case of the embryo it is clear that only the anatomical method can be used, and in the case of the living human being only the physiological, or stimulation, method can be used.