323 



Tl. CA.,.._ 



■sc/, ä. D. 

 tu. I 



1. ch. 



, SCI. a. p. 

 , tv. 



sei. Or S. 



1:1 



^- sei. a. p. 



.'sct.-a. p. 



tv. b, 



tv. b. 



d. ao. 



7. 



ö. 



'^<^ 



Figs. 5, 6, 7, and 8, sections through the wing region of an embryo of one-hun- 

 dred hours. At this stage the wing artery and the Segmental artery of each side arise 

 from a latero-dorsal evagination of the Aorta The sections represent a region 80 [l in 

 thickness (x about 45). 



w.r. Wolfian ridge, scl.a.s. secondary Subclavian artery. Other reference letters 

 as in preceeding figures. 



of the third arch on its anterior 

 side (Figs. 18 and \^ scl.a.s.). 

 This small artery, which is the 

 ultimate Subclavian, starts in an 

 anterior direction, but, turning 

 sharply, it passes superficially 

 to the arches, skirts the auricles 

 of the heart, and in the tissue 



Fig. 9, semi-diagramatic drawing 

 of a section through the same region as 

 Figs. 5, 6, 7, and 8. Reference letters 

 as in the preceeding figures. 



2V 



^/&. A 



