PLATE 8 



EXPLANATION OF FIGCRE 



9 Cross section through the azygos segment of the thoracic duct showing 

 its resemblance to the reptilian type of thoracic duct. 20 mm. Tragulus embryo. 

 Collection No. 202. X 100. 2If, aorta; 28, azygos segment of thoracic duct com- 

 pletely surrounding aorta: 51, azygos vein. 



236 



