Organized bodies are not sustained in the same manner. The Author of creation, equally varied in causes and effects, has assigned them different modes of preservation. Vegetables, which are the lowest in the scale of living things, are fed by roots, which, implanted in the native soil, select by the action of a peculiar mechanism, different subjects, which serve to increase and to nourish them. As we ascend the scale we find bodies gifted with animal life and deprived of locomotion. They are produced in a medium which favors their existence, and have special and peculiar organs which extract all that is necessary to sustain the portion and duration of life allotted them. They do not seek food, which, on the contrary, comes to seek them. Another mode has been appointed for animals endowed with locomotion, of which man is doubtless the most perfect. A peculiar instinct warns him of the necessity of food; he seeks and seizes the things which he knows are necessary to satisfy his wants; he eats, renovates himself, and thus during his life passes through the whole career assigned to him. Taste may be considered in three relations. In physical man it is the apparatus by means of which he appreciates flavors. In moral man it is the sensation which the organ impressed by any savorous centre impresses on the common centre. Considered as a material cause, taste is the property which a body has to impress the organ and to create a sensation. Taste seems to have two chief uses: 1. It invites us by pleasure to repair the losses which result from the use of life. 2. It assists us to select from among the substances offered by nature, those which are alimentary. In this choice taste is powerfully aided by the sense of smell, as we will see hereafter; as a general principle, it may be laid down that nutritious substances are repulsive neither to the taste nor to the smell. It is difficult to say in exactly what the faculty of taste consists. It is more complicated than it appears. The tongue certainly plays a prominent part in the mechanism of degustation--for, being endued with great muscular power, it enfolds, turns, presses and swallows food. Also, by means of the more or less numerous pores which cover it, it becomes impregnated with the sapid and soluble portions of the bodies which it is placed in contact with. Yet all this does not suffice, for many adjacent parts unite in completing the sensation --viz: jaws, palate, and especially the nasal tube, to which physiologists have perhaps not paid attention enough. The jaws furnish saliva, as necessary to mastication as to the formation of the digestible mass. They, like the palate, are gifted with a portion of the appreciative faculties; I do not know that, in certain cases, the nose does not participate, and if but for the odor which is felt in the back of the mouth, the sensation of taste would not be obtuse and imperfect.