THE SKULL 



295 



In the higher Primates including man, the post-orbital bar 

 not only persists but actually extends inwards, forming a 

 complete partition between the orbit and the temporal fossa. 

 It may be mentioned that the alisphenoid bone of the mammal 

 is an ossification of the ala temporalis, which corresponds 

 roughly to the ascending process of the ptery go- quadrate of 

 the reptile. The mammalian alisphenoid therefore represents 



Fig. 148. 



-Palatal view of a skull 

 of Varanus. 



Fig. 149. — Palatal view of a skull of 



a dog, showing the false palate. 



An arrow is passed through the 

 nasal passage. 



the reptilian epipterygoid,both being really parts of the splanch- 

 nocranium. It follows that the so-called " alisphenoids " of 

 fish, reptiles, and birds, which are ossifications of the primitive 

 wall of the brain-case, have nothing in common with the 

 mammalian alisphenoid. Their proper name is laterosphenoid. 

 In birds as in mammals, the brain has undergone great develop- 

 ment and enlargement, and so it happens that in the bony 



