6èô 



Dr. HARRIS H. WILDER, 



are transverse sections and that in reality the inner arms are the 

 longitudinally extended inner edges of the arytenoids. The motion, 



Woodcut I. 



Dorsal 



Dorsal 



V^entral 



Ventral 



accordingly, is that of a partial rotation of longitudinally extended 

 cartilages about their larger axes rather than that of simple rods as 

 would appear from the figure. 



The primordial type. While studying the above relations 

 I became convinced that we have here an unusually primitive larynx, 

 which may give a clew to its phylogenetic origin. The accompanying 

 figures, (II A and B) are diagrammatic transverse sections taken from 



A 



Woodcut II. 



Dorsal 



Dorsal (Dilatator) 



Ventral 



Ventral (Constrictor) 



the adult larynx in its two regions, A being the region of Jhe sphincter 

 ftction and B that of the lever. These may be also taken to represent 



