16 THE STRUCTURE OF THE FOWL 



of the skull lodges the brain and contains the 

 organ of hearing, while the facial part, placed 

 in front of the cranium and niovably connected 

 therewith, comprises the skeleton of the jaws 

 and the hyoid bone. 



Fig. 3. — Skull, Lateral View. 



O., occipital ; P., parietal; Op., optic foramen ; F., frontal ; 01., olfactory foramen ; 

 I.S., interorbital septum; L., lachrymal; X., na.sal ; I., incisive; PI., palatine; 

 T., tympanic cavity; Q., quadrate; Q.J., quadrato-jugal ; J., Jugal ; ^L, maxilla; 

 Pt., pterygoid; Z.p.f., zygomatic process of frontal; Z.p.t., zygomatic process of 

 temporal ; O.c, occipital condyle ; A, articular; D., dentary. 



Early fusion of the individual bones causes 

 them to lose their independence before the 

 chick leaves the egg. Viewed from the exterior, 

 the cranium conveys the impression that its 

 internal capacity is greater than is actually 

 the case. This is owing to the circumstance 

 that its component bones are formed of two 



