BY R. BROOM. 1$^ 



Section D(fig.5) is near the posterior end of the nasal capsule, 

 and shows the paraseptal still of large size. The septum is only 

 well differentiated at its base, which is clearly trabecular. The 

 upper part is unchondrified, and may perhaps belong to the 

 capsule. A portion of the alinasal is seen to the outer side of 

 the nasal cavity. The section is through the anterior end of the 

 cranial cavity and some of the branches of the olfactory nerve. 



Section E (Pl.xi., fig.6) is through the pituitary opening and the 

 anterior part of the alisphenoid cartilage. The trabeculse are 

 oval on section, and separated from each other. Between them 

 the stalk of the pituitary body is seen, and above them the 

 anterior part of the hypophysis. At some little distance outside 

 of the trabecula and a little below the level of it, is seen the 

 large, round, alisphenoid cartilage. It lies in the base of the 

 palatal ridge. Outside of it and above it lies the maxillary 

 branch of nerve v. The orbitosphenoid band, though not 

 chondrified, can be distinctly seen. 



Section F(fig.7) is through the posterior part of the alisphenoid 

 cartilage, and shows the basal cartilage perforated for the carotid 

 artery. Only a very small bar of cartilage lies outside of the 

 artery. A little further out is the still rounded alisphenoid 

 cartilage. Directly above it lies the very large Gasserian 

 ganglion, while above the ganglion can be seen the orbitosphenoid 

 band. The liyoid and the thyrohyal cartilages are both seen 

 articulating w4th the basihyal, and below the thyrohyal the 

 thyroid cartilage is so situated as to suggest that it is serially 

 homologous with the hyoid and thyrohyal, and represents the 

 second branchial arch. (They are omitted from the figure). 



Sections G and H are from embryo B, as the head of this 

 embryo has been cut so that the sections of the posterior half 

 are more directly transverse than in embryo C. 



Section G(fig.8) is through the anterior part of the auditory 

 capsule. The basal cartilage is flat and narrow. The capsule is 

 of large size, but not very distinctly chondrified. At the lower 

 part the uncoiled cochlea is seen in section. Above it is a portion 

 of the cochlear ganglion of nerve viii.; and to the outer side 



