THE ENTIKE SKULL 



499 



Fio. 401. 



FIG. 402. 



-p-tn. 



THE SKULL, SEVEN DAYS AFTER 

 . BIRTH. 



(Natural size.) 



The pterygo-alisphenoidal suture traverses the external pterygoid 



fossa from the anterior to the posterior end. The anterior lateral fon- 



tanelle persists ; the membranous area in 



the inner wall of the orbit is narrowed by 



the growth of the neighboring bones. The 



upper and posterior part of the lachrymal 



is membranous. In this skull, as in many 



other young skulls, the orbitosphenoid is 



pierced by a small temporary foramen ante- 

 rior to the optic foramen ; and a fissure in 



the ethmoidal plate of the palatine extends 



upward from the spheuo-palatine foramen. 

 The ossification in the fourth piece of 



the lateral ethmoid has extended to the 



plate behind the cleft and half-way up 



the first and second pieces. The lower 



part of the 

 mesial piece, 

 including its 



entire cleft plate, is ossified, but is as yet 

 separate from the other parts. The ossifi- 

 cations in the sixth and seventh pieces 

 have increased in size, but are still sepa- 

 rate from each other and from the fourth 

 piece. A small separate centre now 

 appears at the extreme anterior end of 

 the fifth piece. All the scrolls of the 

 lateral ethmoid are very simple : even 

 that one of the fourth piece which later 

 will subdivide to form the mass of small 

 anterior scrolls 4'" (Fig. 306) is a single 

 plate which closely resembles the human 

 middle turbinate bone in being deeply 

 concave on the lateral surface. 



In the skull at eleven days (Fig. 



402) the supraoccipital is larger than the interparietal. The petro- 



mastoid has increased in length, and so greatly in width that it touches 



the squamous and parietal in front and the exoccipital behind ; hence 



THE SKULL, ELEVEN DAYS AFTER 

 BIRTH. 



(Natural size.) 



