Meyer, M. F. (1922). The Other-One is equipped with a sense organ particularly suited to signals. In M. F. Meyer, Psychology of the other-one: An introductory text-book of psychology (pp. 293-312). Columbia, MO, US: Missouri Book Co.
http://dx.doi.org/10.1037/13615-013
A reflex, we know, presupposes a chain of nervous conductors leading from a definite sensory point to a definite motor point. But it also presupposes that this motor point is properly equipped with a motor organ. And it further presupposes that the sensory point is adequately equipped with a sense organ. We learned that in general the most efficient signals are acoustic signals. We therefore ask, now, what Nature has done in order to enable animals to respond properly to acoustic signals. When the acoustic signals are complex and the proper reflex (or habit) response depends on condensation of the nervous functioning called forth by a multiplicity of acoustic signals, we speak of "perception," and here customarily of "auditory perception." We can, therefore, repeat our last question in the following form: How has Nature equipped that sense organ upon which the Other-One's social reflexes particularly depend, that sense organ which serves the Other-One's auditory perceptions, his "auditory organ" or, briefly, ear? Nature's first problem then consisted in modifying the skin of animals living in water or air so that density changes, that is, pressure changes, of the water or air could very easily bring about in sensitive cells chemical changes--excitations. The so-called lateral-line organs of the fishes are such modifications of the skin. However, the pressure changes acting ordinarily on the lateral-line organs of the fishes are still very great in comparison with the pressure changes which we call sound, caused by minute trembling motions of objects at distances often very considerable. Nature found that a sense organ of extraordinary sensitiveness could be constructed by letting the sensitive cells end in fine hairs and by exposing these hairs in such a manner that the slightest pressure changes in the medium surrounding the animal would effect a bending of these hairs. (PsycINFO Database Record (c) 2016 APA, all rights reserved)