662 



Jacob Parsons Schaeffer 



Fig. 34 and 35 Photomicrographs of frontal sections through the left nasal 

 fossa in the region of the bullar folds from a term fetus (series D, slides 5 and 6). 

 Note the bullar folds, the cells in the concha media, and the superior bullar 

 fold in fig. 34. In fig. 35, which is a section farther dorsal, the ostia of the cells are 

 shown. It shows how the suprabullar furrow or recess tends to develop or pouch 

 behind and lateral to the bullar folds; this in time causes the bulla to become shell- 

 like. 



F. furrows, = frontal furrows; cc. eth. ant , = cellulae ethmoidales anterior; 

 Inf. eth., = infundibulum ethmoidale; D. na-sc;/., = ductus nasolacrimalis; <?. max*., 

 = sinus maxillaris; Sbr., = suprabullar recess or furrow; Cr. eth., = cellulae eth- 

 moidales; S. m., — sinus maxillaris; Con. nas. med., = concha nasalis media. 



The infundibular fold or concha. The infundibular fold is very 

 rudimentary and more or less inconstant. It is located lateral 

 to the infundibulum ethmoidale and in part forms its lateral 

 wall (fig. 35). It is more or less separated from the inferior bul- 

 lar fold by the shallow infrabullar furrow. It usually loses its 

 identity in the adult, in that it imperceptibly passes to the bul- 

 lar surface by the obliteration of the infrabullai- furrow. Occa- 



