A CLINICAL STUDY OF THE SKULL. 49 



That deviations from the vertical plane, which so commonly occur 

 in- the nasal septum, might be coimected in some Avay with the 

 changes that take place in the region of the nasal plate is not im- 

 probable. It is known that the parts at the root of the nose are 

 exceedingly firm, and that the nasal bones vary greatly in diameter 

 from the outer to the inner surface. It is also known that the per- 

 pendicular plate of the ethmoid bone is of inconstant proportion, 

 but on the whole tends to advance. Hence, the nasal plate of the 

 frontal bone may be compressed between these opposed directions 

 of growth ; but if the naso-frontal parts are preteruaturally fixed 

 the perpendicular plate of the ethmoid bone may be deflected, or 

 the entire septum be forced to expand in a region whose boundaries 

 have been already fixed. 



The external nose during the period of transition from childhood 

 to adult life changes greatly in shape. It is probable that at this 

 time the substitution from the nasal plate to the nasal spine takes 

 place, and that the deviation in some way correlates with the shape 

 of the nasal bones in the adult. In the negroes, in whom the nasal 

 bones are small and flattened, both at the root and the bridge (the 

 juvenile shape), the process in question retains the plate-like form, 

 while in other races the prominence of the root and bridge is asso- 

 ciated with increased frequency of change of the nasal plate to the 

 nasal spine ; but in the alteration last named the increase of sep- 

 tal deviation is also to be noticed, and an obliteration of the har- 

 monic apposition of the spine with the perpendicular plate of the 

 ethmoid is likely to occur. 



Enough has been observed to warrant the tentative conclusion 

 that a cause for deviation of the septum (especially in that portion of 

 the septum into which the perpendicular plate of the ethmoid en- 

 ters) exists at the junction of the nasal spine of the frontal bone 

 and the ethmoid, together with the rate and character of the change 

 in the forms of the nasal bones. 



While this is a conclusion which the premises in many instances 

 validate, it is true that no one explanation suffices for the explana- 

 tion of all deviations. (See p. 45.) 

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