CONTENTS. 



Int roduetion 7 



Technique 7 



( leiieral uiuilysis of the primitive venous system 1 1 



The' veins of the Wolttian body. 1'2 



Cieneral survey (it the veins 12 



The posterior cardinal vein. . I -I 



The mesial cardinal vein ... 14 



The anterior mesial vein of the \Voltlian licidy. 1 ."i 



The ventral vein of the Wolffian body 15 



The transverse veins of the Wolllian body 



and the vena cava . . 15 



Tlie general circulation of the WolHian bodies .... 17 



^.zygos and hemiazygos veins . IS 



General survey is 



Circulation of a typical body-wall segment 



with relation to the azygos veins 20 



I >rinin and development of the azygos system 

 and the lower segment of the inferior vena 



cava from a prcvertebral plexus _'-' 



Conclusions 'J'.l 



Bibliography . .'id 



Explanation of plates. . :;i 



