60 The Dancing Mouse 



As material for their anatomical work they made use of 

 four dancers, one albino mouse, and four common gray mice. 

 The ears of these individuals were fixed, sectioned, and 

 examined microscopically in connection with parts of the 

 brain. In all, eight dancer ears and six common mouse 

 ears were studied. 



Very extensive descriptions of these preparations, together 

 with measurements of many important portions of the ear, 

 are presented in their paper, the chief conclusions of which 

 are the following : 



1. The semicircular canals, the ampullae, the utriculus, 

 and the cristae acusticae of the canals are normal in their gen- 

 eral form and relations to one another as well as in their 

 histological conditions (2 p. 529). This is contradictory 

 of the statements made by Rawitz. 



2. There is destruction of the macula sacculi (2 p. 534). 



3. There is destruction also of the papilla basilaris coch- 

 leae, with encroachment of the surrounding tissues in vary- 

 ing degrees. 



4. There is diminution in the number of fibers of the 

 branches and roots of the ramus superior and ramus medius 

 of the eighth nerve, and the fiber bundles are very loosely 

 bound together. 



5. Similarly the number of fibers in the inferior branch 

 (the cochlear nerve) of the eighth nerve is very much reduced. 



6. There is moderate reduction in the size of the two 

 vestibular ganglia as a result of the unusually small number 

 of nerve cells. 



7. The ganglion spirale is extremely degenerate. 

 There is therefore atrophy of the branches, ganglia, and 



roots of the entire eighth nerve, together with atrophy and 

 degeneration of the pars inferior labyrinthii. The nerve 

 endings are especially degenerate (2 p. 534). 



