A simple chemical stimulator was developed which permitted the placement of 1 droplet of fluid on the side of a single papilla. The subjects were usually able to determine the quality of a salty, sour, sweet, or bitter test solution for each papilla. The quality to which each papilla was sensitive did not change when the test solutions were placed on different areas of the wall of the papilla. Furthermore, the taste quality did not change with the concentration of the solution, even when the sensation magnitude was increased. There were some papillae which were a combination of 2 or even 3 different papillae. Such combinations occurred mainly on the edge of the tongue and on the soft and hard palates. A photographic map of the tip of the tongue was made and every papilla was marked with its reported quality. It turned out that each papilla gave the same quality response for chemical and for electrical stimulation. This seems to indicate that single papillae are sensitive only to one specific taste quality. Unfortunately, the technique for observing this phenomenon is very time consuming, mostly because adaptation makes long intervals necessary between observations even of threshold values.