It is far from being impossible that Mr. Waterton and Mr. Wells on one side, and Mr. Audubon and his party on the other, may be both correct, for in different species of vulture the power of smell may greatly differ; we know that it does among carnivorous quadrupeds, which seek their prey, some chiefly by sight, others by their acuteness of scent. Among reptiles, the sense of smell appears to be at a low ratio, nor can we suppose that it is acute in fishes. In fact, in fishes the nasal cavities are rudimental, and do not communicate with the organs of respiration. They are nothing more than blind sacs, placed one on each side in front of the head, with two external openings appertaining to each sac. The principal entrance is valvular, and on a curiously plaited membrane in the sac itself, or on tufted or arborescent filaments, are the ramifications of the olfactory nerves distributed. That fishes are attracted or repelled by the odorous effluvia of bodies, diffused either through the water itself or through the air which the water contains, is too well ascertained to be denied. Fishes, in fact, are attracted by certain odoriferous substances, and anglers often use baits impregnated with some volatile oil.[20]
[20] On this subject see Izaak Walton's "Complete Angler."
We cannot for a moment doubt that insects smell; that ants and bees are greatly directed by this sense in their search after food; that carrion-loving beetles are thereby guided from a distance to their repast; that the flesh-fly is led to putrescent animal substances; and we know that the flesh-fly is sometimes deceived by the smell of certain plants emitting a cadaverous odour, and deposits her eggs upon them, the larvæ perishing for want of proper food. In what organ the senses of smell in insects are placed does not appear very plain, and the like observation applies to the crustacea, as crabs and lobsters, for which baited traps are set, and into which they are allured by their sense of smell.
No distinct organs of smell have been discovered in the mollusca, yet it is incontestable that some of these creatures are capable of appreciating odours. We cannot suppose that in the highly-organized and savage cuttle-fish this sense is wanting; and we know that snails and slugs are attracted from a distance by the odour of the favourite plants or fruits on which they feed. The garden slugs are fond of animal food, as we can testify, and they will pick bones with relish; we have seen the hollow of a marrow-bone thrown into the garden filled the next morning with slugs, which had completely cleaned it.
Whether the bivalve mollusks, as mussels, oysters, clams, etc., have any definite sense of smell, we cannot ascertain, but we conjecture that they are endowed with the sense of taste, for they know what to accept and what to refuse.
We have said that man derives pleasure or disgust from the exercise of the sense of smell, and is greatly directed thereby what to choose and what to avoid; yet this sense harmonizes with those of sight, hearing, and more particularly of taste, to render this world delightful to us, if we use God's gifts aright. Has he not scattered the loveliest flowers in garden and meadow? Has he not created fruits that gratify alike the sight, the touch, the taste, and the smell? Has he not spread the beauties of nature around us? Was not the garden of Eden prepared for our first parents? Yes; but sin has entered the world, and over flower and fruit has been the "trail of the serpent."
A few passages from the Scriptures, on which we need not comment, will serve to show the figurative notice of, or reference to this sense by the sacred writers, in order to influence the mind of man through an appeal to his own sensations. "An odour of a sweet smell, a sacrifice acceptable, well-pleasing to God," Phil. iv. 18. Works pleasing to the Lord, deeds of charity and mercy, done by the believer as a testimony of his lively faith, and a proof to the world that faith engenders good works; such works, and not those of the pharisee, are an odour acceptable to God. "Walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweet-smelling savour," Eph. v. 2. Let us, who call ourselves Christians, so walk, that our conduct before men may be after the pattern of Him, who, in love to a fallen race, offered himself as a sacrifice fragrant unto God the Father, that we might escape the sword of justice. When Noah offered burnt-offerings on the altar, "the Lord smelled a sweet savour," Gen. viii. 21; and to Him even now, O reader, will be fragrant true penitence and faith in that Mediator, of whom the sacrifices under the primitive dispensation were but types, and in this sense only did they waft incense to the throne of the Almighty! The language is altogether figurative; but how pertinent to our feelings, and therefore how clear to our understanding, and how forcible!
5. Touch.—Of all the senses, not one is so important to us as that of tact or touch. It is the foundation, as it were, of all our knowledge of the material world, and according to their elevation in the scale of being do animals enjoy this sense in greater perfection, and possess organs in which it is more especially concentrated. We here distinguish, between mere feeling and touch. We consider the wings of the bat, and the antennæ of insects, rather as feelers than as organs of exact appreciation. The sense of feeling is diffused over the whole surface of our body; but the sense of touch, so far as man is concerned, resides in the hand, and especially in the pulpy tips of the fingers.
It is true that we use the word feel when we test the qualities of bodies with our hands, and in this sense our hands are feelers. But we derive a knowledge from the use of our hands, which no other animal derives from the exercise of any organ of tact it may possess. Nor is this to be wondered at, for in all other animals tact or touch administers only to their physical necessities. For example, the sense of touch in the pulpy end of the beak of the snipe or woodcock must be exquisite—multitudinous are the nerves supplying that part—for even the soft worm or larva in the oozy ground is felt, and the finger of man would most probably fail here; but in man the sense of touch appeals to the mind, and communicates mental pleasure, mental instruction, or even mental disquietude. Even as discords in music, or grating sounds, such as the filing of a saw, or the rubbing of cork against a wall, excite the nervous system through the mind, so does the sense of touch disturb the mind and body when that which is touched is discordant. A lady of the writer's acquaintance, by no means timid, and by no means afraid of snakes, was induced to let a common snake glide through her hand; she bore the sensation with firmness, but she nearly fainted when the snake had crept through her grasp, and described the working of the reptile's ribs and abdominal plates as communicating an indescribable sensation. Yet that snake was a sort of pet, and she used to stroke its head, and feel its lambent tongue quiver against her hand. She was not afraid, but the sensation jarred like discordant notes.
Were persons to write down their experiences of the pleasing and unpleasing sensations derived through the medium of the different senses, and were those notes collected together, we should have a mass of most interesting and instructive information, well worthy the study of a physiologist. After all, however, the sense of touch or tact gives less pleasure to man than that of sight, hearing, taste, or smell; it appreciates neither colours nor harmony, nor the flavour of luscious viands, nor the odour of flowers and perfumes; but it communicates greatly to his store of information. It is a "matter of fact" sense, and though an old poet has said—