II. THE MUSCLES OF THE HEAD. 



INCLUDING THE MUSCLES OF THE LINGUAL APPARATUS, 

 TRACHEA, AND THOSE OF THE EYE AND EAR. 



Divide the skin completely around the entire beak, at 

 its base ; divide the platysma myoides close to its origin, 

 on either side, and allow its giilar portion to come away 

 with the integument as it is removed ; in like manner, 

 divide, on either side, close to their origins, the circum- 

 conchse and dermo-temporalis. Carefully reflect back- 

 wards the entire skin, so as to expose the neck for at 

 least its upper third. Open the bird's mouth to its full 

 extent, and pack sufficiently with soft tow, so as to 

 render the muscles of the tongue and trachea more 

 prominent. 



The muscles here to be examined are the intrinsic 

 muscles of the head, and are in no way attached to the 

 vertebral column. They are the following : — 



14. The temporal. 18. The pterygoideus internus. 



1.5. The masseter. 19. The pterygoideus externus. 



16. The biventer maxillaj. 20. The digastric.^ 



17. The entotympanicus. 



1 This group of muscles (14-20 inclusive) are presented by Gadow 

 in his well-known memoir on the morphology of Aves in Bronn's 

 Klassen, vi. Band, pp. 318-325, where tliey are illustrated by 



