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cases, however, there may be an area above, or more often below the 

 colon, where the peritoneum and perhaps coils of small intestine come 

 into contact with the pancreas. The youngest specimen in which I 

 observed the colon adherent to the head of the pancreas was 9 cm in 

 length. There is considerable variation in regard to this and other 

 details, but the fact remains that in the great majority of foetuses 

 beyond the fourth month the transverse colon is adherent to the 

 anterior surface of the duodenum and head of the pancreas, and that 

 the transverse mesocolon persists only on the left side of the mid-line. 

 If this be the usual condition in the new-born, the question natu- 

 rally arises as to how it might be transformed into what is usually 

 described as the adult condition, viz., a complete transverse mesocolon, 

 the line of attachment beginning at the hepatic flexure and passing 

 horizontally to the left across the duodenum and the head of the 

 pancreas. While not denying the possibility of such a transformation, 

 I do not believe that it actually takes place. It seems to me more 

 probable that the relations described by Birmingham (2), i. e., the 

 transverse colon adherent to the duodenum and head of the pancreas, 

 represent the type found in the majority of adults. In other words, 

 the relation established in the foetus persists in the adult ^). 



II. Body of the Pancreas. 

 The body of the pancreas, soon after its appearance in the em- 

 bryo, presents the same subdivisions as in the adult, being connected 

 on the right with the head of the pancreas by a more or less con- 

 stricted neck and being in contact at the left extremity with the 

 spleen. In regard to its direction, which is exceedingly variable, we 

 may distinguish four types, — the horizontal, ascending, ascending- 

 horizontal, and ascending-descending. In the horizontal type, 

 which is the rarest, the body extends nearly horizontally outward 

 from the upper part of the head. This type occurred in only three 

 out of the twenty-four foetuses (5,5 cm to "50 cm in length) in which 

 the direction was carefully noted. It may rarely even extend outward 

 and slightly downward, but there is certainly no justification for the 

 statement of Wiart (15) that this seems the normal type in the new- 

 born. In the ascending type (present in seven out of twenty-four 



1) It may be noted here that in order to determine the peritoneal 

 relations in this region with accuracy, the subjects must be hardened 

 by intravascular injection of formalin. Otherwise a narrow area of 

 adhesion may readily be mistaken for a short mesocolon, since the peri- 

 toneum is very elastic and easily stretched. 



