320 Jacob Parsons Schaeffer. 
erste Hauptmuschel.’’ This ridge has its free border directed 
superiorly, and it extends in a ventrosuperior direction. It early 
tends to form a shallow groove immediately superior to it, which 
is the primitive infundibulum ethmoidale (Recessus inferior des 
absteigenden Astes der ersten Hauptfurche of Killian). To be 
Fic. 3 (X 10). Drawing of a reconstruction of portion of the right nasal 
cavity of an embryo aged 120 days. The drawing includes the meatus, infundi- 
bulum ethmoidale, and the sinus maxillaris. Only that portion of the cavity, 
was modeled so as to include the sinus maxillaris and its relations. Since it 
represents cavity it is a negative. 
Note the very extensive ostium maxillare in comparison to that in fig. 2. 
M. NS., = meatus nasi superior; M.N.M.,M.N.1, = meatus nasi, medius 
he inferior; I. E., = infundibulum ethmoidale; C.N., = cavum nasi; H. S., = 
ttaius semilunaris; O. M., = ostium maxillare; S. M., = sinus maxillaris. 
accurate, then, we must say that the maxillary pouch evagi- 
nates from the primitive infundibulum ethmoidale —a part of the 
meatus nasi medius. 
Some time after the appearance of these structures there is 
a more or less uneven bulging on the lateral wall of the primitive 
