Thus, by the completion of growth in the circumvallate and the foliate papillæ and by the degeneration of the fungiform (loss of taste buds) the region of greatest sensitivity is transferred from the tip to the sides and back part of the tongue, while the zone just back of the tip becomes entirely taste blind. _Taste in the Adult_ The most striking characteristics of taste in the adult as compared with that of the child, then, is what appears to be a gradual reduction in the extent of distribution of taste sensitivity and a shifting of the region of the greatest sensitivity. No doubt there are other changes, e.g., a general reduction in delicacy of taste analogous to the sort of change which is noted in the other senses as age advances. In extreme old age such a condition is quite pronounced. In hearing, for example, there is not only a dulling sensitivity but a shortening of the range of audible pitches, especially in the region of the higher pitches. So, on the tip of the tongue, sensitivity may be very much reduced or disappear entirely. These changes in taste are not commonly brought to one’s attention as are those of sight and hearing, because they affect our life less vitally. But there is little doubt that careful tests would reveal them. _Structural and Functional Differences Among Individuals_ It has been suggested that individuals differ considerably in the distribution and function of their taste mechanism. In the search for general laws these variations within the limit of normality have been looked upon as troublesome exceptions and not of much interest. And these differences are no doubt responsible for the lack of agreement among investigators on many points. For instance, there are persons whose sensitivity on the tip of the tongue is so poor that sweet tastes can be aroused only with the aid of tongue movements. This and other similar cases have given cause for the belief in the necessity of tongue movements for arousing all taste sensations. Some investigators have found the tonsils and the uvula sensitive, while others have found them insensitive. When one finds such conflicting statements from men like Nagel and Kiesow, individual differences seem a plausible explanation. No special studies have been made of these individual differences. Consequently, about all that one can say is that the distribution of the taste buds in different people is subject to considerable variation and that on this account one cannot definitely mark out the limits of their distribution which shall hold for all persons. The same is true of the distribution of sensitivity to specific taste stimuli, sweet, sour, bitter, and salt substances. Such vague statements as are usually made, namely, that sweet is best tasted upon the tip of the tongue, sour upon the sides, bitter upon the back, and salt over nearly the whole tongue, are true, but when one attempts to assign definite limits to these