FOWL SECOND AND THIRD DAYS 



533 



It is advisable to make a careful study of the anatomy of an 

 embryo of about the stage shown in Fig. 235 or 236. l 



s.a. 



ot. 



H. 



~ a.e 



ita. 



tf 



I'l". - ; !.">. Third-day Fowl embryo with the vascular area. 



".>, edge ofaranlou; }:, eye; //, heart; ot, otocyst; .-.-. s,n,-amniotic connexion; g.t, sinus 

 terminahs; /../, tall-fold; -./. vib-llin,- aiteiy; . portion ot splanchnopliMiiv involute.! to forma 

 nvi'ss roun.l th- hcud of tlie t-mbryo. 



1 It is customary to mount transverse sections with the posterior or tailward surface 

 of the section next, the slide: consequently the figures represent the sections as seen 

 from in front and the side of each figure towards the right-hand side of the 

 corresponds to the left-hand side of the embryo. 



