THE CELLULE ETHMOIDALES 



47 



FIG. 13. DIAGRAM DRAWN FROM A HORIZONTAL SECTION JUST ABOVE THE 

 ANTERIOR ATTACHMENT OF THE CONCHA SUPERIOR. (Series A, No. 13 

 (one-hundred-and-twenty-six-day fetus), slide 10, section 1. X 3.) 

 Specimen shows the processes of pneumatization developing superiorly into 

 the lateral masses of the ethmoid, thus forming the primitive cellulse eth- 

 moidales. Sept.na., Septum nasi; Infund.eth., infundibulum ethmoidale; 

 Cel.eth.ant., cellulse ethmoidales anterior; Cel.eth.post., cellulse ethmoidales 

 posterior; Epi., epithelial invagination from meatus superior. 



FIG. 14. DIAGRAM DRAWN FROM A HORIZONTAL SECTION JUST BELOW THE 

 ANTERIOR ATTACHMENT OF THE CONCHA MEDIA OF A FETUS ONE HUNDRED 

 AND TWENTY-SIX DAYS OLD. (Series A, No. 13, slide 14, section 1. X 3.) 

 Shows well the relations of the developing infundibulum, the hiatus semi- 

 lunaris, and the bulla ethmoidalis. Ag.na., Agger nasi; Infund.eth., infundib- 

 ulum ethmoidale; H.semi., hiatus semilunaris; B.eth., bulla ethmoidalis; 

 C.sup., concha superior; C.med., concha media; Proc.unc., processusuncinatus; 

 Sept.na., septum nasi. 



