FIGURE 148 



148 Transverse section through ventral portion of upper thoracic; region 

 a 16 mm. eat embryo (series 222, slide X, section 2), X 225. 



1 Sympathetic nerve. 



3 Right Azygos vein, thoracic portion. 



6 Precardinal or precava of left side. 



7 Aorta. 



8 Oesophagus. 



9 Trachea, 



10 Pulmonary artery. 



22 Vagus. 



36 Thoracic duct, azygos segment. 



37 Broncho-mediastinal duct. 



