Lateral Wall of the Cavum Nasi in Man. 667 



conchae have coalesced with one another, thus constricting off 

 small blind pouches (early anterior ethmoid cells), or whether the 

 frontal furrows in anticipation of anterior ethmoid cells have 

 pouched toward the frontal region, thus closely simulating coal- 

 escence between the several frontal folds, but making coales- 

 cence only apparent rather than real. 



A comparison of figs. 36 to 42 (showing both frontal sections 

 and surface views of the frontal recess and the descending ramus 

 of the meatus medius) will materially aid in clearing up the various 

 adult conditions one meets in these regions, in connection with 

 the gross anatomy and relations of the nasofrontal duct, the 

 infundibulum ethmoidale, and the bulla ethmoidalis. 



The accessory fold or concha of the 7neatus nasi superior. At 

 this juncture mention must again be made of a rather frequent 

 accessory concha that is differentiated rather early on the lat- 

 eral wall of the descending ramus of the meatus nasi superior 

 (fig. 45). Seydel directs attention to it in the following words: 

 "Bei menschlichen Embryonen fand ich einige Male in dem 

 Spalt zwischen der mittleren und obern Muschel, also an der 

 Stelle, wo bei den Halbaffen die zweite Nebenmuschel liegt, eine 

 niedrige leistenformige Erhebung der seithchen Nasenwand 

 . Ich mochte diese Bildung als Rest der Nebenmuschel 

 deuten." 



The anlage of this accessory concha is indicated rather early, 

 and by the fourth month of fetal life it is well established (fig. 

 19). Killian considers this fold important as a point for orienta- 

 tion: "Die Nebenmuschel im Bereiche der zweiten Hauptfurche 

 ist, wenn nachweisbar, ein vorzugliches Orientirungsmittel 

 namenthch zur Bestimmung des Crus descendens 3," i.e., the 

 crus descendens of my concha nasalis superior. Some earlier 

 writers thought that the concha superior developed or became 

 differentiated from the concha media — this because of the fur- 

 row that is very frequently found on the medial surface of the 

 descending crus of the concha media in the fetus ffig. 22). Seydel 

 later pointed out the error of this contention, and Zuckerkandl 

 agreed that he previously was in error in saying that the 'mit- 



