THE EMBRYOLOGY OF THE BIRD S LUNG 



467 



Lat.moi.v 



Pul.Vn.- 



P.lnt.ScH- 



Fig. 17 Camera tracing of the cai)illary network on the dorsolateral surface 

 of the left lung of an embryo at the close of the eighth day of incubation. Drawn 

 by Mary Head. 



Fig. 18 Surface view of the hmgs of an embryo at the close of the ninth day 

 of development. Right bronchus cut and lung rotated so as to expose the mesial 

 surface. Abd.sc, abdominal air-sac; ^.f/iir.sc. , anterior intermediate air-sac, with 

 primordiaof recurrent bronchi (Rer.Br.) •.Ceri'.sc, Cervical air-sac; Lat.moi., lat- 

 eral moiety and Ulcsjuoi., mesial moiety of the interclavicular air-sac; P.intr.sc, 

 posterior intermediate air-sac. 



