No. I.] THE VERTEBRATE EAR. 245 



the Frog without producing the least disturbance of equilibrium, 

 so Tomaszewicz was able in her experiments on bony fishes to 

 remove the semicircular canals without the fish showing the 

 slightest traces of a disturbance of equilibrative power. These 

 results agree entirely with those obtained by Kiesselbach in his 

 successful operations. Finally, Cyon demonstrated that these 

 motions and equilibrious conditions could not be due to the 

 functions of the canals, since the same phenomena occurj^ed after 

 section of the auditory nerve, and that rotation of a mammal in 

 this condition brought on vertigo the same as in entire animals, 

 completely exploding the dynamical theory. 



Notwithstanding these investigations, Helmholtz (1877, 120), 

 in the last edition of his Tonempfindungen, p. 249, practically 

 adopts Goltz's view. Older experinients by Valentin and Schiff, 

 in which these investigators had been successful in cutting the 

 canals without bringing on motor disturbances, remained un- 

 noticed while the work of Flourens, Brown-Sequard, Breuer, 

 Mach, and Crum Brown, who had not succeeded in cutting the 

 nerves or canals without such disturbances appearing, were 

 given more weight than was their due. Cyon's experiments in 

 1878 on Petromyzon were always followed by motor disturb- 

 ances, but such a result was to have been expected, owing to the 

 compactness of the parts and the practical impossibility of isolat- 

 ing the canals in such an operation. 



The following observations, cited by Baginski, to whose ac- 

 count I am indebted for these important facts, were made by 

 H. Munk on a Dog which had for several months suffered with 

 dizziness and malposition of the head. Examination showed 

 that the trouble was caused by a distension of the tympanic 

 cavity with a liquid exudation. This fluid had not entered the 

 canal complex, and apparently had not caused lesion of the latter 

 nor of the brain. Here was a case showing symptoms similar 

 in all respects to those following the experiments of Flourens 

 and Cyon on resection of canals in mammals. 



A solution of the ear canal problem might be possible if the 

 relation of the ear canals in this case to the abnormal symptoms 

 could be determined, but this could not be done owing to the 

 impossibility of operating upon the canals in mammals without 

 at the same time injuring the cerebellum, owing to its closeness 

 to the ear and the very intimate relation of both structures to 



