NASOFRONTAL REGION IN MAN 



133 



conchae; provided, of course, these structures were differentiated. 

 As stated before, there are instances in which the lateral wall 

 of the recessus frontalis does not become configured by pits and 

 folds (fig. 5). In some specimens the adult anatomy is so altered 

 that interpretation is very difficult, even impossible. 



It may be well here to i-efer to specific dissections of the 

 region for study and analysis. In figure 6, for example, we 

 have represented an adult nasofrontal region exposed for study 

 by the removal of the operculating concha nasalis media. There 



Sm/JS fro f /talis _ _ . 

 Ductijs }icfsofro7iTc(h 

 Co7/.cha 7tas.??ied 

 l//ffj,r/d7b. eth . . , ^ 

 Proc. uncinatjjs . , . 

 Ostium ?nax. ace. 



ft lIuIcK eth . ant. 



.Bulla ak 



Sjf/us sptief/aidalis 



^ Nifpoptii^sis cerebri 



fo/irtia //as. suprema JT 



Co/icJia //ffs.s/j//re///al 



Fig. 6 From an adult. Recessus frontalis and nasofrontal connections ex- 

 posed for study by the removal of part of the concha nasalis media. See text 

 for a discussion of this dissection. 



is positive evidence of four embryological frontal furrows or pits. 

 The first or most ventral of the latter differentiated into a cellula 

 ethmoidalis anterior of small dimensions communicating directly 

 with the meatus nasi medius, medial to the processus uncina- 

 tus. The third and fourth frontal furrows or pits likewise de- 

 veloped into cellulae ethmoidales anterior both of which com- 

 municate with the meatus nasi medius cephalic to the hiatus 

 semilunaris of the infundibulum ethmoidale. 



