FIGURES 160 AND 161 



160 Transverse section of dorsal portion of upper thoracic region in a 13.5 cat 

 embryo (series 189, slide VII, section 20), X 225. 



161 Same, section 21. 



I Syinpatlietic nerve. 



16 Dorso-medial somatic venous t ril)Ut:iri('s. 



17 Prevert('l)r:il xcuous plexus. 

 22 Vagus. 



25 Internal jugular vein. 



77 Mesenchymal intercciliil:n- l\iiipliatic aidages. 



