Fi(;rRK 107 



107 Transverse section of ventral part of upper thoracic rejiion in a lo iniii. cat 

 embryo (series 107. slide IX. section 40), X 225. 



3 Right prcraxal vein. 



4 Atrojjhying cnitiryonal \"cin. foi'ming kernel in inlcrior of ({(^clopinsi 



and replacing lyni])hatic space. 



5 Extraintinial or perivenous lynipiiatic space surrounding degenerating 



embiyonal vein. 

 7 .\orta. 

 '.I Trachea. 

 10 l'uhnonar\- artcfx' 



