FIGURES 32, 33 AND 34 



32 Same, section 41. 



33 Same, section 42. 



34 Transverse section through left side of lower cervical region in a 14 mm. cat 

 embryo (series 212. slide IX, section 24), X 200. 



1 Sympathetic nerve. 



8 Oesophagus. 



11 Jugular lymph sac. 



12 Jugular lymph sac, thoracic duct approach. 



16 Dorso-medial somatic venous tributaries. 



17 Prevertebral venous plexus. 



18 Peritracheal venous plexus. 

 22 Vagus. 



24 Thyrocervical artery. 



25 Internal jugular vein. 



