132 J. PARSONS SCHAEFFER 



its duct (ductus nasofrontalis) and certain of the cellulae eth- 

 moidales anterior that drainage from these paranasal chambers 

 finds its way in whole or in part into the infundibulum eth- 

 moidale, thence via the latter into the sinus maxillaris. 



ADULT AXAT0:MY 



In order to properly interpret points in adult anatomy it is 

 frequently necessary to resort to the embryology of the part or 

 parts involved. This, indeed, is true of the nasofrontal region. 

 Doubtless many of the erroneous statements extant in the 



Hecessas fro?itaih _ '<nius &onra/K< 



Bvlla efJi..,^ 1 ^^l i" (^or/fJt» /u/s. vr/fd. 



Mu7/cfih.cf //.... ^^' i , ^ "^* ^up/^balJarfhrrow 



m//a(^o/ cc. ef//f/mdal('S} 



7}-oc.rjncinatus 



Fig. 5 From a child aged fourteen montlis. Note the apparent al).sence of 

 frontal furrows and folds. The whole recessus frontalis is expanding or growing 

 frontalward in the establishment of the sinus frontalis. After SchaefTer. 



literature on the nasofrontal connections are the result of draw- 

 ing conclusions from a study of too few specimens, of studying 

 adult material alone, and of errors in interpretation due to the 

 fact that embryologic and adult studies were not carried on 

 simultaneously. 



The adult nasofrontal region presents a varied anatomy, a 

 fact in accord with the varied genesis of the parts involved. In 

 the adult one usually finds evidence of the previous embryologic 

 condition that must have obtained in the particular case. Careful 

 analysis of the nasofrontal region reveals, as a rule, the deriva- 

 tives of the frontal furrows or pits and of the frontal folds or 



