The physiology of mind : an interpretation based on biological morphological, physical and chemical considerations / by Francis X. Dercum.

  • Francis Xavier Dercum
Date:
1925
Catalogue details

Licence: In copyright

Credit: The physiology of mind : an interpretation based on biological morphological, physical and chemical considerations / by Francis X. Dercum. Source: Wellcome Collection.

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    the water—currents and the like—possibly facili¬ tate the changes implied by oxidation, but do nothing else. Soon, however, in the metazoa we observe the appearance of small cavities— vesicles—which contain one or more particles of solid mineral matter and which constitute an apparatus by means of which the movements, the vibrations, of the surrounding medium are taken up—arrested as it were—and thus for¬ cibly transmitted to the substance of the organ¬ ism. Such an apparatus, though it is termed an ear, an otic vesicle, may take up movements far coarser than those which in ourselves give rise to sound. Again, in fishes there is, in addition to a well-differentiated ear, an apparatus which extends in linear form from the head on each side of the body to the tail. It is known as the lateral line system and consists of a tube having at intervals an open space closed by a mem¬ brane beneath which is found a structure in¬ distinguishable in its essential features from a macula acustica. Each such macula contains epithelial cells bearing hair-like appendages and each is surmounted by a small jelly-like mass containing a few granules of mineral matter. It is exceedingly probable that this apparatus,