EMBRYOLOGIC CONSIDERATIONS 



31 



Orbit. 



:' .':/ 



FIG. 8. DIAGRAM DRAWN FROM A CORONAL SECTION JUST POSTERIOR TO 

 THE RECESSUS SPHENO-ETHMOIDALIS, SHOWING THE PRIMITIVE SINUS SPHE- 

 NOIDALES WHICH DEVELOP AS IMAGINATIONS OF MUCOSA INTO THE POS- 

 TERIOR NASAL CAPSULE. (Series A, No. 3 (sixty-five-day embryo), slide 10, 

 section 10. X 16.) 



S.sph., Sinus sphenoidales; Cart. cap. na., cartilage capsulae nasalis; Sept.na., 



septum nasi. 



