The Sinus Maxillaris in Man. S17 
turbinals that especially concern us in the development and 
relations of the primitive sinus maxillaris. 
Killian terms the naso-turbinal and the subdivisions of the 
ethmo-turbinal, ‘‘Hauptmuscheln;”’ and the smaller projections 
appearing in the furrows between these ‘‘Hauptmuscheln,”’ as 
‘“Nebenmuscheln.’’ What he terms ‘‘die zweite Hauptmuschel”’ 
will be spoken of in this paper as the concha nasalis media (first 
ethmoidal concha). 
The naso-turbinal plus the processus uncinatus and the concha 
nasalis media have marked bends, thus presenting ascending 
and descending crura. Correspondingly the furrow between 
these conche has a bend, and presents ascending and descend- 
ing limbs. For the sake of description we will consider the 
processus uncinatus as the descending crus of the naso- 
turbinal. The primitive meatus nasi medius has, therefore, as 
inferior boundaries the cura of the naso-turbinal and the space 
existing between the conch nasales, media and inferior. The 
superior boundaries of the space are the crura of the concha 
nasalis media (zweite Hauptmuschel of Killian) (fig. 4). To 
say then, as has been done earlier in this paper, that the maxillary 
pouch evaginates from the space separating the primitive conch 
nasales, inferior and media, is not giving the pouch its definite 
location. The actual point of this primary pouching is from 
the primitive infundibulum ethmoidale, or the ‘‘unterer Re- 
cessus des absteigenden Astes der ersten Hauptfurche”’ of 
Killian. 
This pouch is a minute epithelial sac, and forms the Anlage 
of the sinus maxillaris. Its earliest establishment precedes the 
appearance of the cartilage which later surrounds it. This is 
in accord with the statement of E. Kallius, that 
: die Nebenhdhlen der Nase schon angelegt sind, 
ehe dee Knorpel entsteht, und dass also das Skelett sich erst sekundir 
um jene herumlegt. 
"The relation of the space existing between the conche nasales, inferior and 
media, to the descending ramus or limb of the first furrow is spoken of thus by 
Killian, ‘“‘Der Raum zwischen zweiter Hauptmuschel und unterer Muschel ist 
demnach nur eine Art Vorhof zum absteigenden Theil der ersten Haupfurche.’’ 
