In order to secure the full advantages accruing from the use of the jaws and their appendages, it is, above all, necessary for them to be adequately exercised during the period of development. If this is done, not only will the tendency to dental caries, adenoids, indigestion, and other evils be greatly diminished, but the masticatory instinct will establish itself as a permanent force, so that the individual will tend for the rest of his life to subject even soft foods to thorough mastication. The tongue, the lips, and the jaws of the newly born child find their natural exercise at the mother’s breast, and we should, therefore, do our utmost to get the mother to suckle her child, the bottle affording neither the same kind nor the same amount of exercise. If, unhappily, we fail in this, we must see that the teat of the feeding-bottle is so constructed as to compel the child to earn his meal by, at any rate, some exercise. This kind of exercise promotes the growth of the tongue and thus of the jaws, especially of the mandible. Directly the infant shows a disposition to bite hard things the instinct should be gratified. We may observe a tendency in this direction as early as the third or fourth month, and it becomes more and more pronounced when, the time for the eruption of the teeth approaching, the gums begin to swell up and to get tender, and saliva begins to flow from the mouth; it is now, more than ever, necessary to provide the child with hard substances on which to exercise the jaws and the gums, and a great deal of the trouble of teething is due to the failure to recognise this fact. What, then, are we to employ for this purpose? I am convinced that it is a mistake to rely solely, or even mainly, upon baubles of ivory, coral, and the like useful though these may be in their way; it is far better to give the child something which is not only hard but nutrient and pleasant to the taste, something which will at one and the same time exercise the maxillary apparatus, excite the gustatory organs, and provide a certain amount of nutriment. To this end we may, as the teething time approaches, give a chop or chicken bone, from which most of the meat has been removed; by powdering the bone with white sugar or salt we may increase its attractiveness. From such bones a good deal of nutriment can be extracted, and this of a kind which is most acceptable to the infant stomach, for it must be remembered that the young human is in the main carnivorous. Indeed, since milk is a purely animal diet, all the mammals must be regarded as essentially carnivorous during the period of suckling, while man, as already observed, from the time he emerged from the anthropoid until he learned to cook his food, was throughout life mainly an animal feeder. Therefore we should not hesitate to allow the teething infant animal food in the form suggested. Chicken and chop bones, yielding as they do before the pressure on the gums, are,