ORGANS OF SPECIAL SENSE 287 
5.9 mm. head-length, he identifies it positively as a rudimentary 
organ of Jacobson. 
The septal gland arises on the eighth day from the inner 
wall of the vestibulum, opposite the base of the vestibular tur- 
PF coe 
° prc 
2 
eo seses 
ar 
a2 
22 
Fic. 165. — Transverse section of the olfactory organ of a 
chick embryo, of 7.5 mm. head length. (After Cohn.) 
f., Line of fusion. e.n., External nasal process. 1. n., 
Internal nasal process. T. 1, T. 2, Intermediate and supe- 
rior turbinals. 
binal, as a solid cord of cells. This grows backwards in the nasal 
septum and passes to the outer side and branches, subsequently 
acquiring a lumen. 
