SIDE OF THE HEAD. 131 



ptery go-palatine arteries. The external pterygoid process is 

 seen at 8, and between the two processes, is the pterygoid 

 fossa, which is occupied by the internal pterygoid muscle. 

 On the outer side of the external pterygoid process i^ the 

 zygomatic fossa. The internal pterygoid process is long and 

 narrow, having at its apex the hamulus, and at its base the 

 scaphoid fossa from which arises the circumflexus or tensor 

 palati muscle. 



Side of the Head. 



Those portions of the side of the head which are formed by 

 the frontal, parietal and occipital bones, and by the squamous 

 part of the temporal, require no explanation here ; but the 

 region which is behind the malar and upper maxillary bone, 

 and within the zygomatic processes of the temporal and malar 

 bones, which comprises part of the temporal and zygomatic 

 fossae of some anatomists, is both important and obscure. 



To obtain a view of this, the lower jaw should be removed, 

 and the zygoma sawed away, in one preparation ; and in 

 another, the upper maxillary and palate bones of one side 

 should be applied in their natural position, to the os sphenoides, 

 without any of the other bones. 



The upper part of this region, formed by the sphenoidal, 

 frontal and malar bones, is made concave by the form of the 

 external angular part of the os frontis and of the os malse ; 

 which projects backwards so as to cover a large portion of it. 



The lower part is formed principally by the external surface 

 of the pterygoid process of the sphenoid bone, and by the 

 posterior surface of the upper maxillary. Between the lower 

 end of the pterygoid process and the upper maxillary bone, a 

 small portion of the os palati intervenes ; but in many adult 

 subjects it is not to be distinguished from the other bones. At 

 this place, the pterygoid process and these bones appear to be 

 in close contact ; but as they pass upwards they recede from 

 each other so as to form a considerable aperture, which 

 continues the whole length of the pterygoid process. This 

 fissure, which may be called pterygo-palatine or pterygo- 

 maxillary, would open into the posterior part of the cavity of 



