162 THE SKULL. [CHAP. 



and the suture between it and the maxilla is only obliterated 

 in aged specimens. It generally extends upwards on the 

 side of the anterior nares, so far as to meet the nasal and 

 completely exclude the maxilla from taking any part in the 

 boundary of this opening. 



The lacrymal foramen is never situated externally to the 

 orbit, although, in the lower forms, it may be close upon 

 the margin. 



As in Man the postorbital process of the frontal meets 

 the orbital process of the malar so as completely to encircle 

 the outer side of the orbit ; and an extension backwards and 

 inwards of these bones joining the alisphenoid divides the 

 orbit from the temporal fossa. 



The nasal bones vary much in length and breadth, but 

 they present the peculiarity throughout the order of a great 

 tendency to ankylose together in the middle line, even at a 

 comparatively early age. 



In all the smaller and middle-sized Monkeys the general 

 surface of the calvaria is oval and smooth, but in the larger 

 Baboons and Orangs there are well-marked supraorbital, 

 sagittal, and occipital ridges. These attain their greatest 

 development in the adult male Gorilla, where they com- 

 pletely mask the original form of the cranium. Their size, 

 in this sex, appears to increase with age ; while in the 

 oldest females, on the other hand, they are but slightly 

 apparent. 



The paroccipital process is always rudimentary, as in 

 Man. 



The squamosal in the higher forms is developed much as 

 in Man ; but in the lower forms it is more reduced, and 

 takes a smaller share in the formation of the side wall of 

 the cranium. It generally comes in contact, at its upper 

 anterior angle, with the frontal, but not in the Orang or in 



