110 



ALEXANDER S. BEGG 



described, after the obliteration of the vitelline trunk, essentially 

 normal relations would be restored. But in the pig the superior 

 mesenteric vein would cross in front of the duodenum, and it is 

 probable that this condition will some time be found in adult 

 animals. 



V. lien. 



V. lien. 



V. mes. sup. 



V. mes. sup. 



V. lien. 



V. mes. sup. 



Fig. 5 Diagrams showing, in ventral view, the variations observed in the peri- 

 intestinal venous rings. The probable position of the obliterated portions is 

 indicated by stippled vessels. ^4, normal human embryo. B, abnormal pig em- 

 bryo. C, abnormal human embryo. V.lien., splenic vein. V.mes.sup., superior 

 mesenteric vein. Y.p.. portal vein. Y.v.. trunk formed by the fusion of the vitel- 

 line veins. 



BIBLIOGRAPHY 



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 Elze, C. 1907 Beschreibung eines menschlichen Embryo von zirka 7 mm. 



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