44 THE TONER LECTURES. 



The smaller varieties exhibit relatively long palatal crests when, 

 indeed, they occupy one-third or one-half of the septum at the 

 choanse plane. Since this arrangement is seen in the foetus at term, 

 and the openings are oval or sub-rounded, it is fair to assume that 

 the small oval variety is a form of arrested development. In a case 

 of atresioe nasi seen in an adult I detected this variety of choanal 

 shape. The small oval form is so often met with in clinical studies 

 that the conclusion may be tentatively drawn that it aids in retain- 

 ing mucus in the nasal chambers, and in this way an anatomical 

 factor may materially aid in establishing a morbid state. For ex- 

 amples in adult crania see a skull of a Miami Indian^ and a Me- 

 nominee.^ In immature skulls, an Armenian,^ an Austrian,* a 

 Czech,'^ a Genoese,** a Sandwich Islander,'' a Ruthene,* and a Nea- 

 politan.' 



. It is well to remember, as already stated, p. 29, that it is possible 

 to have the image of the choanse, as seen by the rhinal mirror, nar- 

 rowed by thickening of the internal pterygoid process of the sphe- 

 noid bone. 



4. The Floor of the Nasal Chamber. 

 In many subjects the plane of the lower border of the nostril is 

 higher than that of the floor of the chamber. The inferior turbi- 

 nal lies a variable distance within this depression. The finger 

 when inserted into the nostril will not, in such cases, enter the in- 

 ferior meatus, but will pass into a space which is defined by the 

 septum on the one hand and the upper part of the inferior turbi- 

 uals on the other. An example of the skull showing the dej^ressed 

 floor is seen in a Menominee^" Indian. 



5. Deviations of the Septum. 



When it is recalled that the bony septum is composed not only of 



the vomer and the perpendicular plate of the ethmoid bone, but 



1 No. 1052. 2 jfo_ 1222. 3 No. 53^ (j^i. ^f phyg., 6 years. 



* No. 60, Col. of Phys., 16 years. * " 80, " " 17 " 



6 u 213 u u 12 " 7 " 143 " " 1(3 " 



8 u 19^ <c u 7 u 9 u ]12_ u u 9 <i 



10 No. 44. 



