NASOFRONTAL REGION IN MAN 145 



adult. The topographic relationships may, however, be very 

 intimate, i.e., they may be contiguous. 



4. The ductus nasofrontalis (or the sinus frontalis) and the 

 infundibulum ethmoidale are occasionally directly continuous in 

 the adult. 



5. The infundibulum ethmoidale in approximately as many 

 as 50 per cent of adult bodies acts as a channel for the carriage 

 of secretion or infection from the sinus frontalis and certain of 

 the cellulae ethmoidales anterior to the sinus maxillaris: In- 

 cluded in this group are (a) those cases in which the sinus fron- 

 talis and the infundibulum ethmoidale are continuous, and (b) 

 those cases in which the sinus frontalis and the infundibulum 

 ethmoidale are discontinuous, but intimately and vitally related 

 topographically. 



THE AMERICAN JOURXAL OF ANATOMY, VOL. 20, NO. 



