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Walter A. Baetjer 



thoracic duct appears as a plexus of vessels along the aorta in which one 

 can see two definite channels, one on either side. Or one may say that 

 the duct is double with numerous anastomoses. Between the kidneys 

 and reproductive organs is the large mesenteric sac from which vessels 



Fig. 9. — Transverse section through the early cisterna chyli and mesenteric 

 sac in an embryo pig, 3 cm. long. The section shows the connection of the 

 receptaculum chyli and the mesenteric sac, by large channels along the lateral 

 margins of the aorta. A., aorta; C. C, cisterna chyli; E., kidney; M. 8., 

 mesenteric sac; /., Intestine; P. C. V., post-cardinal vein. 



spread to the capsule of the kidneys. The cisterna chyli is directly 

 behind the mesenteric sac, separated from it by the aorta and hence can- 

 not show in the figure. The posterior lymph sacs are opposite the lower 

 end of the Wolffian bodies, and from these sacs vessels are seen passing 

 to the legs. 



To sum up briefly, then, the following conclusions may be noted : 



