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Page:Popular Science Monthly Volume 39.djvu/856

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836
THE POPULAR SCIENCE MONTHLY.

ground, and by its foot-organ knows all that is passing there. This otolithic apparatus is admirably well adapted to give notice to the mollusk or to the insensitive armor of the crustacean of the least disturbances that pass through the mass into which it is plunged. Every one is acquainted with the experiment of the balls in contact series. A disturbance reaching the end of the chain is betrayed only by the last ball, which is free, and expends in oscillations the shock that is transmitted to it. Equally well known is the process of placing in contact with the vibrating body, plate, or membrane a light substance—sand or cork—the oscillations of which reveal a vibration which our eyes can not discover on the trembling body. In the same way every disturbance traverses the indifferent mass of the animal, and the otolith free in the otocyst, collects it, and announces the slightest shocks to the nervous tissue on which it reposes. The preotolithic formations serve in a similar way. Animals furnished with otoliths can thus analyze rhythms and disturbances which are synthetized in our cochlea into sounds of different tones. The otolithic bell can only reveal a trepidation, and continues unfit to provoke a continuous sensation other than that which results from the persistance of nervous, terminal, or central impressions, a limit beyond which it can not estimate the pitch without such an arrangement as that of the cochlear formations.

As does the spider in the center of its web, stretching with its weight all the vibrating cords that converge toward its fore legs, furnished with otoliths, so can any insect standing on slight legs, stiff and flexible at once, which draw from the ground the slightest tremblings as its antennae do from the air, distinguish between a thousand significant disturbances, without, after all, perceiving any sensation like what we call sound.

There are, in fact, two fundamental senses which are two forms of touch. The first is immediate touch, under the form of contact when the surface of the object is accessible, or of smell or taste when it is in a state of division, in which it is revealed by its molecular atmosphere. The second touch, at a distance, which is extremely varied, comes by means of the modification of an interposed medium originating in the object that is perceived. Perceptions of electricity and heat are common to both forms.

We ought, a priori, to refuse to attribute to insects, whose sensorial organs are so different from ours, senses like those of man. Should not their psychology with more reason be referred to them as a class than to ours? And while it may be legitimate for man to expect to find some of his feelings among the vertebrates which have the most evident relationship with him, that inverse anthropomorphism has a curious appearance which lends our thoughts, wishes, needs, senses, and affections to beings so differ-