The Dancing Mouse 



sensory structures, or nerve supply of the ear of the dancer, 

 which serve to explain the behavior of the animal, it is prob- 

 able that there are unusual structural conditions in the brain, 

 perhaps in the cerebellum, to which are due the dance move- 

 ments and the deafness. The work of Panse is not very con- 

 vincing, however, for his figures are poor and his descriptions 



meager ; neverthe- 

 less, it casts a cer- 

 tain amount of 

 doubt upon the 

 reliability of the 

 descriptions given 

 by Rawitz. 



The unfavorable 

 light in which his 

 report was placed 

 by Panse's state- 

 ments led Rawitz 

 to examine ad- 

 ditional prepara- 

 tions of the ear of the dancer. Again he used the recon- 

 struction method. The mice whose ears he studied were 

 sent to him by the physiologist Cyon. 



As has been noted in Chapter IV, Cyon discovered certain 

 differences in the structure and in the behavior of these 

 dancers (n p. 431), which led him to classify them in two 

 groups. The individuals of one group climbed readily on the 

 vertical walls of their cages and responded vigorously to sounds ; 

 those of the other group could not climb at all and gave 

 no evidences of hearing. After he had completed his study 

 of their behavior, Cyon killed the mice and sent their heads 

 to Rawitz ; but unfortunately those of the two groups became 

 mixed, and Rawitz was unable to distinguish them. When 



ff 



FIGURE 8. The membranous labyrinth of the 

 dancer's ear. Type I. This figure, as well as 9 and 

 10, are reproduced from Rawitz's figures in the Archiv 

 fur Anatomie und Physiologic, Physiologische Abthei- 

 lung, 1899. C.s., anterior vertical canal; C.p., posterior 

 vertical canal; C.e., horizontal canal; U., utriculus. 



