668 Jacob Parsons Schaeffer. 



tlere Siebbeinmuscher (concha superior) was differentiated from 

 the 'untere SiebbeinmuscheF (concha media). Zuckerkandl 

 then advances the theory ''dass die mittlere Siebbeinmuschel 

 nicht nur aus einer Teilung der Concha ethmoidaHs inferior 

 hervorgeht, sondern liber derselben und unabhangig von ihr sich 

 entwickelt und als Rudiment in der unteren Siebbeinspalte 

 steckend angetroffen wird." It appears that Zuckerkandl in speak- 

 ing of the variations of the 'mittlere Siebbeinmuschel/ at times 

 mistakes the accessory concha of the superior meatus for his 'mittlere 

 Siebbeinmuschel' (concha nasalis superior). What he desig- 

 nates as the 'Anlage der mittleren Siebbeinmuschel,' (Tafel VII, 

 Fig. XI, ISormale und pathologische Anatomie der Nasenhohle 

 und ihrer pneumatischen Anhange, Bd. I, Wien und Leipzig, 

 1893) certainly corresponds to my accessory concha of the supe- 

 rior meatus, and not to my concha nasalis superior. 



In case the accessory concha of the superior meatus is well 

 developed we have fairly well formed superior and inferior reces- 

 ses. The inferior recess is especially deep in the cases where the 

 'crista suprema' of Killian is well developed (fig. 45). This con- 

 dition makes the superior meatus look much like the middle 

 meatus, i.e., the accessory concha of the superior meatus takes 

 the place of the bulla ethmoidalis (accessory concha of the middle 

 meatus), and the 'crista suprema' takes the place of the processus 

 uncinatus (compare figs. 18 and 45). 



The inferior recess of the superior meatus may continue supe- 

 riorly and ventrally into the blind superior termination of the 

 superior meatus. The accessory concha is, however, at times 

 wholly or in part coalesced with the concha media, thus obliter- 

 ating wholly or partly the inferior recess. Frequently a posterior 

 ethmoidal cell develops from the inferior recess. The superior 

 recess is often obUterated by coalescence between the accessory 

 concha and the concha superior. In other instances the superior 

 recess may be continued ventrally and superiorly to the blind 

 end of the meatus superior. Occasionally an ethmoid cell devel- 

 ops from this recess. 



