184 



Nachdruck verboten. 



The Branches of the Superior Mesenteric Artery to the Jejunum 



and Ileum. 



By Thomas Dwight, M. D., LL. D., 



Parkman Professor of Anatomy at the Harvard Medical School. 



It is surprising, especially in view of the great development of 

 abdominal surgery of late years, that the arteries of the small in- 

 testine below the duodenum should not have been described more 

 accurately. I have looked into some twenty of the leading works in 

 English, German and French without finding a single description that 

 seems to me at all adequate. The general account, in brief, amounts 

 to this: that a dozen or twenty branches arise from the left of the 

 superior mesenteric artery, that they presently subdivide, and their 

 inosculating branches form a first series ot arches. From the con- 

 vexity of this first tier the same thing is repeated on a smaller scale. 

 This often, or usually, occurs a third time, and perhaps a fourth or 

 a fifth. Finally from the last arch, vessels (not particularly described) 

 pass to the intestine. The most remarkable deficiency of the above 

 description is that the attention seems to be concentrated on the arches 

 and that no mention is made of the very important system of straight 

 vessels, vasa recta, which extends throughout the Jejuno-Ileum, ex- 

 cept, perhaps, at the lower end. This is the more surprising as there 

 are plenty of correct figures representing these vessels. Although the 

 possibility of four of five superimposed arches is mentioned, next to 

 nothing is said as to the part of the intestine at which the greatest 

 complexity is to be expected. 



1 presented a paper on this subject to the Association of American 

 Anatomists which was printed in the Proceedings of 189 8. I was 

 not present to read the paper myself, and occupied with other things, 

 I neglected to have any reprints made. Consequently the paper has 

 remained entirely unknown, and as the Proceedings of the Association 

 no longer appear as a series but have been absorbed into the Ame- 

 rican Journal of Anatomy, it may be considered as absolutely lost. 

 I therefore beg leave to present it again in a somewhat different form. 

 The following description is the result of the observations of several 

 years. Though I believe it to be correct I do not doubt that many 



