Structural Peculiarities and Behavior 63 



ance of the peripheral sense organs. Furthermore, there 

 are no anatomical facts which would indicate a lack of gal- 

 vanic dizziness (2 p. 552). 



Despite the fact that they seem to explain all the functional 

 peculiarities of the dancer, the statements made by Alexander 

 and Kreidl are neither satisfying nor convincing. Their 

 statements concerning the structure of the ear have not been 

 verified by other investigators, and their correlation of struc- 

 tural with functional facts lacks an experimental basis. 



In this connection it may be worth while to mention that 

 a beautiful theory of space perception which Cyon (9) had 

 constructed, largely on the basis of the demonstration by 

 Rawitz that the dancers have only one normal canal, is totally 

 destroyed by Panse, Baginsky, Alexander and Kreidl, and 

 Kishi, for all of these observers found in the dancer three 

 canals of normal shape. Cyon had noted that the most 

 abnormal of the voluntary as well as of the forced movements 

 of the dancer occur in the plane of the canal which Rawitz 

 found to be most strikingly defective. This fact he con- 

 nected with his observation that the fish Petromyzon, which 

 possesses only two canals, moves in only two spatial dimen- 

 sions. The dancer with only one functional canal in each 

 ear moves in only one plane, and neither it nor Petromyzon 

 is able to move far in a straight line (up. 444). From these 

 and similar surmises, which his eagerness to construct an 

 ingenious theory led him to accept as facts quite uncritically, 

 Cyon concluded that the perception of space depends upon 

 the number and arrangement of the semicircular canals, and 

 that the dancer behaves as it does because it possesses canals 

 of unusual shape and relations to one another. The absurd- 

 ity of Cyon's position becomes obvious when it is shown that 

 the structural conditions of which he was making use do not 

 exist in the dancer. 



