424 



DR. R. BROOM ON THE 



Text-fip-. 53. 



A. Diagrammatic representation of articulation in Dicynodon, 



B. Articulation in tbe Cyfioclotlt, Cynognatlixis. 



C. Hypothetical diftgram of the condition when the dentary articulates with the 



squamosal. 



D. Hypothetical diagram of the condition when the articular and aSgular no longer 



support the jaw. 



E. Hypothetical diagram of the condition when the articular and angular take on 



their auditory function. 



r. Diagram repfesenting the perfecting of the auditory function (the mammalian 

 condition). 



