250 AVERS. [Vol. VI . 



the sections of two like canals of two sides of the head, since 

 a certain relation of the direction of the pendular motions to the 

 canals cut had been noticed. Although the evidence thus 

 gathered together is still insufficient to explain wholly the 

 phenomena under consideration, it nevertheless points unmis- 

 takably to the central origin of these disturbances. All the 

 phenomena following canal section in mammals and in birds 

 are nothing more than the results of brain lesions such as are 

 entirely adequate to explain the phenomena. 



Baginski concludes from his own observations that '' Soviel- 

 steht indess fest, dass die meisten vorliegenden Untersuchun- 

 gen fiir die Behauptung, dass die Bogengange die peripheren 

 Organe des Gleichgewichtunns sind, dessen Centrum in Klein- 

 hirn sich befindet, den Beweis nicht nur nicht erbracht haben, 

 sondern dass im Gegentheil dieselben ganz und gar gegen diese 

 Annahme sprechen " ; and further that "Wir wissen, ja iiber 

 die Funktion der Bogengange trotzt aller bisherigen Unter- 

 suchungen iiberhaupt nichts." 



Retzius had already called attention to Breschet's discovery 

 that the auditory nerve was divided into two branches, each of 

 which supplied semicircular canal organs. But the canal experi- 

 mentalists have very generally been ignorant of this important 

 fact, and Baginski (1883, 12) introduces it for the first time into 

 this discussion. 



Steiner's (270, 1886) experiments were at first, as he himself 

 has shown, of a nature not likely to give unmixed results, and 

 both in operation and in result were very much like Sewall's. 



However, by improvements in the surgical operations neces- 

 sary to effect the separation of the canals without disturbance 

 to other branches of the auditory nerve than those ending in 

 the ampullae, the experiments were finally made completely 

 demonstrative. 



Steiner was tJius able to remove all six semicircular canals 

 from the ears of the Sharks operated npon without causing the 

 least apparent disturbance to the motor apparatus of these fishes. 

 This experiment he repeated inany times with the uniform result 

 of seeing the fish, when replaced in water, swim off as though 

 anatomically perfect. In this conclusive way is the question 

 settled, — the question of the part played by the semicircular 

 ear canals in the function of equilibrating the body ; and it is 



