262 



On the Vitelline Vein of the Cat 



VV 



Fig. 3. Cat embrj-o of C.2 mm. Har- 

 vard Embryological Collection. Trans- 

 verse Series 380. Section 373. 



the loop of ilenm to enter the coelom. This process was described by 



me in a paper two years ago.^ At 

 birth, and even for a few days after 

 birth;, this free, elongated artery may 

 be easily identified, and, curiously 

 enough, in the cat, remains pervious 

 Ao. ■Lip to the fourth or fifth day. It 

 represents the terminal branch of the 

 superior mesenteric, and in the em- 

 bryo is undoubtedly its largest 

 branch. 



Our knowledge of the liver veins 

 is largely due to the admirable re- 

 searches of Hochstetter, as well as 

 to others who have written on this 

 subject, not to mention what is to 

 be found in the many text-books on 



anatomy. As far as I know, Hochstetter, as well as the others, treats 



of the course and rela- 

 tions of the vitelline 



veins after they have 



reached the duodenum, 



rather than of the first 



part of their course, 



nam.ely, from the yolk 



sac to the duodenum. I 



have found no literature 



relating to this division 



of the subject. Both the 



right and left vitelline 



veins are to be seen in a 



cat embryo of 3 mm. 



They extend from the 



yolk sac, within the duo- 

 denal walls, encircle its 



cavity, and finally termi- 

 nate in the heart 



VV 



Fig. 3. A drawing- of the stomach and duodenum of a 

 cat at birth to show the free vitelline vein joining the 

 Soon superior mesenteric vein. 



after this date the right vein, below the liver, is obliterated, and the 



1 Additional Observations on the Morphology of the Digestive Tract of the Cat. 

 The Journal of the Boston Society of Medical Sciences. Vol. IV., p. 205. April 1900. 



