OF THE ADULT ANTRUM. 



3a 



Fig. 4. 



Large Adult Antrum, capable of containing 8 drams of fluid {transverse section). 



[-^ 



Fig. 5. 



Small Adult Antrum, capable of containing 1 dram of fluid {transverse section). 



There is often a great difference in the size and 

 shape of the cavity, and in the elevation of its floor 



I) 



