SENSES

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SENSES. The internal organs of the five sensesseeing, hearing, feeling, smellin g and tastingare the nerves, small, threadlike fibres, distributed all over the body, and all connected with the brain. (See Nerves.) Few subjects, in comparative anatomy and physiology, have given rise to more various and contradictory opinions than the external organs of sense in some classes. Much misunderstanding on this point has arisen from the hasty application of inferences drawn from the human subject to other animals. Thus it has been supposed that those which possess a tongue must have it for the purpose of tasting, and that the sense of smell must be wanting where we are unable to trace the existence of a nose. But, in many instances, the tongue cannot, from its substance and mechanism, be considered as an organ of taste, and must be merely subservient to the ingestion and deglutit ion of food ; while in many animals, particularly insects, an acute sense of smell seems to exist, although no part tvm be pointed out in the head which analogy would justify us m describing as the nose. The sense of touch appears to exist only in four classes of animals,in most mammalia, in a few birds, in serpents, and probably in insects; and although all animals may possess that feeling which makes them sensible to the impressions of warmth and cold, very few possess, like the human subject, organs exclusively appropriated to the sense of touch, and expressly constructed foi the purpose of feeling, examining and exploring the qualities of external objects. (See Touch.) The sense of taste, as we have above remarked, does not appear to be confined to the tongue, that member being wanting in many animals which do not seem destitute of the sense; and in many which possess it, the tongue is employed for other and different purposes. (See Taste.) The sense of smelling prevails much more extensively in the animal kingdom than that of taste, since it not only assists several genera in selecting their food, which they have not afterwards the power of tasting, but is also of service in finding out proper objects for the satisfaction of their sexual appetites. (See Smell.) We should naturally expect to find an organ of hearing in most classes of animals, when we consider the various services which this sense performs, as that of indicating the approach of danger, of conducting beasts of prey to their food, &c.; and even in those animals, in which no external organ of hearing is discoverable, the sense is evidently not wanting. (See Ear, and Hearing.) The power of vision is confined to those animals which are provided with eyes for the reception of the images of external objects. Some species, even of the higher orders, are destitute of the organ of vision, which is also entirely wanting in the lower classes of the animal creation. (See Eye, and Optics.) It is by the senses that the mysterious communication between the spiritual soul and the external world of being is kept up. The* manner in which this is done, is unknown to us ; we can trace the operation of outward matter, upon the organized material system, a few steps; but we soon lose sight even of these vestiges, and are obliged to acknowledge our ignorance of the workings of our owa frame. We cannot give even a skeicn of the speculations of philosopher* un this subject. on which the history jf philosophy, in fact, chiefly turns.