A CLINICAL STUDY OF THE SKULL. 43 



lu the skull of an Araucanian^ a large opening is detected in 

 the perpendicular plate at a point directly back of the nasal plate 

 of the frontal bone. Openings elsewhere in the perpendicular plate 

 are so common that no special mention of them need be made. 



The Vomer. — When the vomer at the posterior nares is not at 

 the level of the openings, but lies at its lower part a little way 

 within the chambers, the bone may be said to be recedent. It is a 

 reversion eifect, since it is commonly seen in the skulls of carnivora 

 and in important groups of ungulata. (See p. 31.) 



In a Peruvian ^ skull of five years and a Bengalese ^ skull of six 

 years this recedence may be said to be present. The same pecu- 

 liarity is seen in the aduit skull of a Narragansett Indian,* an 

 Assiniboin,^ a Golgonda,*' a Sioux/ and a Blackfoot.^ 



Recedence is so marked in a Maltese^ skull that the bone unites 

 with the maxillary crest at the raaxillo-palatal suture. There is no 

 upward extension of the spine of the palatal bone. The exact 

 position of the vomer at the choanse in determining the posterior 

 projection of the infei'ior turbinated bone is of clinical importance. 



The vomer may have two grooves — one for the triangular cartillage 

 (it may be so obliquely placed as to appear to belong to the parie- 

 ties) anteriorly, and one for a vein placed far back on the side. 

 Examples of the obliquely placed groove for the triangular carti- 

 lage are seen in an Araucanian^" skull and in several skulls of 

 North American Indians. 



3. The Choance. 

 The choanse vary remarkably in form and dimensions. They may 

 be as large as 23'"'" long by 13'"'" wide, or as small as 13'"'" long by 

 6"""" wide. Usually wide and of a rectangular form inferiorly, as 

 the borders join the transverse palatal process, they may ba oval. 

 The larger varieties include the shape first named, and the smaller 

 one the shape last named. 



iNo. 63. -^ No. 1492; M8 ; *9.3l; M554 ; M-SIS; ^605; 

 8 1227. 9 No. 117 (Col. of Phys.). ^^ No. 651. 



