26 THE TONER LECTURES. 



In one instance the surface is hyperostosed (No. 78, Menominee). 



In three examples the under surface is concave in the centre, and 

 two large canals retained at the sides (1322, Potawatomie ; 1229, 

 Upsala; 1228, Upsarooka). 



The vomer is more or less concave at the ujDper surface, and is 

 adapted to the convex surface of the sphenoid bone; but the method 

 of union of the two bones is not as simple as the above statement 

 Avould imply. The posterior part of the vomer, including the wings, 

 may be without union to the sphenoid bone. The two bones are 

 thus separated by an interval, which is variable with the shape of 

 the body of sphenoid itself. The arrangement suggests that during 

 life either blood-vessels or indifferent tissue occupied the intervals, 

 or that hyperostosis at the anterior part of the sphenoid — probably 

 at the line of the pre-sphenoid — had forced the vomer down and 

 thrown it off from attachment to the posterior part. In immature 

 crania the vomer is very generally removed from the sphenoid pos- 

 teriorly. The disposition seen in the adult skull may be a retention 

 of a juvenile character. If it is not so it is remarkable that the 

 region so commonly exhibits this retardation in nutrition, for it is 

 comparatively rare to see any other arrangement of the ])arts. 



From among all the crania examined but 75 exhibit a departure 

 from the above plan — i. e., in this number of specimens only did 

 the vomer articulate directly with the sphenoid throughout. Is 

 it not strange that tlie description of the union generally 

 accepted should be that of the entire union ? Is it not suggest- 

 ive that the retardation of the processes of development of the 

 region should be greater in the crania of civilized races than among 

 primitive people? The greater number of examples of entire union 

 were found in the ethnological collection of the Academy of Nat- 

 ural Sciences. 



While it is true that the lower animals uniformly exhibit the 

 simple form of union, and on that account the plan may be con- 

 sidered as an instance of reversion, it must be stated that in 65 im- 

 mature skulls (none, however, of the negro or his congeners) exam- 



