398 



VERTEBRATE LIFE AND ORGANIZATION 



Figure 21.3. A dorsal view of the frog's skeleton. Major cartilaginous areas are 

 stippled in this and in other drawings of the skeleton. Roman numerals refer to digit 

 numbers. (After Parker and Haswell.) 



both are parts of the visceral skeleton. Most other skull bones are of 

 axial origin. The names of major ones are shown in Figures 21.3 

 and 21.4. 



The greater part of the visceral skeleton is incorporated in the 

 hyoid apparatus— a plate of cartilage and bone that supports the floor 

 of the mouth and the base of the tongue. 



