618 



B. F. Kingsbury and H. D. Reed. 



Function of the "Sound-Tkansmitting" Apparatus. 

 In order to determine the precise function of the so-called sound- 

 transmitting apparatus in Urodeles a series of experiments upon 

 both larvae and adults is necessary. The skeletal connections of the 

 fenestral elements in the larva, the changes taking place upon the 

 assumption of the terrestrial life and the correlation of structure 

 and habit in certain adults furnishes, however, some basis for judging 

 the function of these structures. 



P.,ot. 



Fig. 21. Schema to illustrate the relation of the ligaments found in this 

 region. Col., columella ; H., ceratohyale ; L.h-c, ligamentum hyo-columellare ; 

 L.h-m., ligamentum hyo-maudibulare ; L.li-s., ligamentum hyo-suspensoriale ; 

 L.s-c, ligamentum squamoso-columellare ; M.G., Meckel's cartilage ; P.asc, 

 processus ascendens palatoquadrati ; P. Ms., processus basalis palatoquadrati ; 

 P.ot., processus oticus palatoquadrati; Pq., palatoquadratum ; St.C, stilus 

 columellse ; Sq., os squamosum. 



It is perhaps not assuming too much to believe that the sound- 

 transmitting apparatus serves as an organ of equilibration and the 

 detection of vibrations of low frequency when such come to the ani- 

 mal through a dense medium such as earth or water. The nature 

 and structure of the apparatus in urodeles seem to preclude the belief 

 that vibrations of any frequency whatsoever can be detected from 

 a medium as rare as the air. There is, however, nothing in the 

 nature of the apparatus to interfere with the view that vibrations 



