316 DRS HEPBURN AND WATERSTON ON THE 



A peritoneal fold of the nature of a great omentum was represented by a short fold, 

 not more than 6 cms. in length, depending from the curvature of the stomach, where 

 it appeared from under cover of the liver, but did not contain any quantity of fatty 

 tissue. The coils of intestine were suspended from the posterior or dorsal abdominal 

 wall by a single mesial fold or mesentery, in which near the root there were large masses 

 of lymphatic tissue, which diminished in size towards the caudal end. The lower end 

 of the intestine passed into the pelvic chamber mesially, and was suspended by a 

 continuation of the mesentery. 



The absence of any intestinal coil corresponding in position to the colon rendered the 

 arrangement of the peritoneum about the stomach and pancreas somewhat unusual. 



The great omentum, already described as depending from the stomach, was composed 

 of four layers of peritoneum — two ventral and two dorsal. On tearing through the 

 ventral layers, a lesser sac of peritoneum was opened, whose boundaries were as 

 follows : — 



Ventrally, the wall of the stomach ; dorsally, pancreas ; on the left, the first 

 chamber of the stomach ; and on the right side, the last part of the stomach and the 

 duodenum. 



No aperture corresponding to a foramen of Winslow could be found, and the arrange- 

 ment of the peritoneal membrane was more clearly brought out by examining it from 

 behind, after removing the viscera en bloc. 



The lesser sac was then seen to be completely closed in by the peritoneum, which 

 had the following attachments : — 



The anterior layers of the great omentum, attached to the greater curvature of 

 chamber No. 2 of the stomach, were prolonged on the left side to the posterior 

 surface of chamber No. 1, from which they were reflected off along an oblique line 

 from the centre of its ventral border to the spleen. 



Above the spleen,the two layers separated to envelop the oesophagus. The two 

 posterior or dorsal layers pass dorsally to the border of the pancreas, where they 

 diverge, one passing on the anterior ventral surface, and the other to the inferior caudal 

 surface of that viscus. 



On the right side, the layers passed on to the duodenum, and then backwards on to 

 the posterior abdominal wall and pancreas, and thus on the right side the lesser sac 

 became completely closed. 



The apex of the pancreas was in contact with the under surface of the liver. 



The absence of an aperture into the lesser sac * may be explained by reference to the 

 relative positions of the stomach, liver, and pancreas. The pancreas, instead of lying 



* In a monograph entitled, " Recherches sur le deVeloppement de la cavite hepato-enterique de l'Axolotl et de 

 l'arriere cavite" du peritoine chez les mammiferes (Lapin), par Albert Brachet, Archives de Biologie, tome XIII., 1893, 

 pp. 559-618 (Plates XXIV. to XXVII.), the following passage occurs : — " La fermeture de cet hiatus" (de Winslow) 

 " chez l'amphibien, provient de ce que le bord posterieur du m£so-lateral est tres peu etendu, et que dans son 

 interieur ne penetre pas le foie. Ce bord, se continuant dans le mesoduod^num a son extremite inferieure, se soude 

 peu a peu a lui, de bas en haut. L' union entre les deux, progressant dans ce sens, aniene Pocclusion de l'hiatus." 



