and their Relation to the Peritoneum. 



485 



therefore be sufficient to recommence at the point at which their 

 description was discontinued. Beginning with the mesogastrium, 

 perhaps it is remembered that although at first very simple 

 (Diagram 4), yet it afterwards grew and descended from the 

 greater curvature of the stomach to form a loop, the great omentum, 

 and that afterwards it ascended to be fastened to the back of the 

 abdomen. If these ascending layers be traced, the innermost, after 

 reaching the spine, passes upwards to form the back of the lesser sac ; 

 the underlayer accompanies it until the spine is reached, and then 

 turns downwards to become continuous with the upper layer of the 



Diagram 5. 



( 







) 









I 











w 



1 



m 



S. Stomach. P. Pancreas. /. Fossa, c. Transverse colon. 



transverse mesocolon (Diagram 5). Of course it is recognised that 

 at this time the colon has an independent mesentery comparable 

 in every way to that of the small intestine, and it is clear that at this 

 juncture an interval separates the under surface of the omentum from 

 the upper surface of the colon and mesocolon. Now in order to 

 explain how these acquire the intimate relation which they have in 

 the adult, Haller simply stated that they became adherent. This 

 view has been adopted by succeeding authors, and if it is true it must 

 follow, as they say it does, that the transverse mesocolon should con- 

 sist of four layers of peritoneum, three above the middle colic artery 

 and one below. Although I have examined a great many subjects, 

 the transverse mesocolon has never appeared to consist of more than 

 two layers, one above the artery and one below. If this is true, 

 Haller's theory becomes involved in doubt, even if other objections 

 could not be urged against it. But it seems pertinent to ask why 

 this process of adhesion only occurs in this particular place and 



2 M 2 



