Mervin T. Sudler 395 



angles. At the bend there is a rounded prominence extending dorsally. 

 Opposite to this prominence the 3rd and -ith visceral pouches project 

 at right angles to the line of the oesophagus and trachea. The 2nd 

 projects downward and is curved oralward. The 1st visceral pouch 

 shows on its cephalic angle a greater degree of prominence than the 

 other part of it. This is the first indication of the outgrowth of this 

 part of the pouch to form the Eustachian tube. In this view there is 



/ 





Fig. 2. Lateral view of the model of the pharynx of the model of embryo II. 

 The embryo is represented as transparent. Mag^nitied 25 diameters. Hyp., hypo- 

 physis; Oe., cesophagus; Tr., trachea, V. P.^ V. P.'^ V. P.'^^ and V. P.'^ first, 

 second, third and fourth visceral pouches. 



much to suggest the model of the rabbit embryo shown by Piersol ' in 

 Fig. 8 of his paper. 



From below the general shape is the same as when seen from above, 

 but the picture is very much complicated by the projection of the 

 visceral pouches, median, thyroid, rudiment, etc. 



From the base of the prominence representing the 1st pouch a ridge 

 runs backward on each side and terminates in the middle line. From 

 the dorsal edge of this angle the median thyroid rudiment arises. It 



" Loc. cit. 



