An exposition of fallacies in the hypothesis of MrDarwin . communicated to the airin the tympanum also strike the round window, andcommunicate with the perilymph in the tympaniticdivision of the cochlea; this in turn acts upon theendolymph, and through it upon the wonderful struc-ture in the lamina spiralis, termed the fibres of Corti,by which the waves are converted into impulses whichcause the sense of hearing in the cochlea ! ^ But the two senses, if I may use the expression, are different. That produced by striking the nerves in the ampullae tends to distinguish intensity or quantity of so
An exposition of fallacies in the hypothesis of MrDarwin . communicated to the airin the tympanum also strike the round window, andcommunicate with the perilymph in the tympaniticdivision of the cochlea; this in turn acts upon theendolymph, and through it upon the wonderful struc-ture in the lamina spiralis, termed the fibres of Corti,by which the waves are converted into impulses whichcause the sense of hearing in the cochlea ! ^ But the two senses, if I may use the expression, are different. That produced by striking the nerves in the ampullae tends to distinguish intensity or quantity of sound; that produced by the fibres of Corti in the > See Fig. 20. ^ Yig. 20, d d d. Fig. 21. 348 FALLACIES OF DARWINISM. cochlea has reference to the discrimination of quality ofsound. Such at least are the opinions of some of ourbest physiologists; but the subject is difficult to study,and we infer rather than state positively that such isthe case. The use of this beautiful structure, the fibres ofCorti of which Fig. 21 is a magnified section, will be. Fig. 21.—Part of the Lamina spiralis of the internal ear, magnified toshow the fibres of Corti. a, first series of fibres, h, second seriesof fibres, one thrown back, c, epithelial cells, d, zona , periosteum by which the lamina spiralis is attached, with spacesbetween the bundles, f, cylindrical elevations of the habena sulcata,after Corti. better understood by the following extract from Pro-fessor Huxleys Elements of Physiology, p. 218 :—- ^ There is every reason to believe that the excite-ment of any single filatment of the cochlear nerve givesrise in the mind to a distinct musical impression, andthat every fraction of a tone which a well-trained ear iscapable of distinguishing is represented by its separatenerve-fibre. Thus, the lamina spiralis resembles akey-board in function as well as in appearance, thefibres of Corti being the keys, and the ends of the THE EAR. 349 nerves representing the strings which th
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