University of California Publications in Physiology Volume 3-4 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...angle depressed; that is to say, the eyes are rotated backward around their visual axes. Rotation around the same axis but inclining the head upward causes the eyes to rotate forward around their visual axes. If the rotation is around an obliquely placed horizontal axis the eye movements are in a corresponding plane; for example, if the animal is held with the head inclined downward and to the right, that is, rotated in the plane of the right anterior and left posterior canals, the right eye is elevated and the left eye depressed, but both eyes are rotated backward around their visual axes. If the animal is rotated around the last mentioned axis but into such position that the head is elevated and inclined to the left, the right eye is depressed, the left eye elevated, and both are rotated forward on their visual axes. All the above described compensatory movements tend to preserve for the eyes the positions in space which they held before the change in position which called them forth. Corresponding movements of the fins occur, and these movements are such as would when combined with the ordinary swimming motions tend to return the body to its original orientation in space. That these movements depend upon some structure in the ear had previously been proved by Loeb,2 who found that they disappeared permanently after section of both auditory nerves. i Lee, Journal of Physiology, Vol. 15, p. 311, 1893, and Vol. 17, p. 192, 1894. 2Locb, Archiv f. d. gesammte Physiologie, Vol. 49, p. 187, 1891, and Vol. 50, p. 66, 1891. Lee found that stimulation of the ampulla of any canal caused movements of the same kind as those brought about by rotation in the plane of that canal. Thus on excitation of the ampulla of the right anterior vertical canal the right eye was el...