Equilibrium, and Vertigo

Abstract

A LTHOUGH the internal ear or labyrinth of man's body is so small that it may be placed within a hazel-nut of moderate size, it contains two organs of the first importance—one for the recognition of sound, the other for the recognition of movement. A hundred years ago anatomists and physiologists had no suspicion that the internal ear was a double organ. When John Hunter discovered that fishes had an elaborate internal ear or labyrinth, with three well-developed semicircular canals, he believed he had established as a fact that fishes are furnished with the power of hearing. The discovery made by Flourens in 1825 that a partial or total destruction of the semicircular canals of a pigeon deprived the bird of all power of controlling its movements was altogether unexpected and puzzling. No one had suspected that the vertebrate animal was furnished with an organ which silently answered the purposes of a mariner's compass, nor could it have been anticipated that such an instrument should form part of the apparatus known as the internal ear or labyrinth.

Equilibrium, and Vertigo.

By Dr. Isaac H. Jones. With an analysis of pathologic cases by Dr. Lewis Fisher. Pp. xv + 444. (Philadelphia and London: J. B. Lippincott Co., 1918.) Price 21s. net.