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214 Proceedings of the Royal Irish Academy, 



XXXIII. — Oif Two DissnnxAE roE:y:s op Peeittphlic Potjches. By 

 AxEXAXDEE Macaxistee, AI.B., Professor of Comparatiye Anatomy, 

 Dublin University. (Vitli Plate 24.) 



[Eead June 14, 1875.] 



In a paper published in Yirchow's Ai-cbiv., 1874, Band. 60, p. 66, 

 Prof. Waldeyer of Breslau gives a resume of all the cases of post- 

 abdominal pouebes of which he has found records, and fi-om these 

 data proceeds to classify these pouches according to their anatomical 

 position, and to suggest the probable cause of the formation of each 

 species. His experience agrees with that of every practical anatomist, 

 that the neighbourhood of the cgecum is that which is most fertile in 

 irregularities, as he catalogues four species which occiu- in this 

 locality. 



Having seen a very large number of these pouches, I was early led 

 to believe that, although it is useful, for convenience, to classify these, 

 yet scarcely two of these perityphlic pouches are alike. This is what 

 one might expect from a few moments' thought on the remarkable and 

 variable changes to which this region is exposed in the coui-se of the 

 development and descent of the caecum, and hence almost every case 

 that occuji's has its own features of interest. 



In the present volume of the"^ Proceedings of this Academy one 

 variety of pouch was described by !Mr. Leeper, under the name of 

 recessus refroccecalis, a pouch which, though belonging to a genus of 

 fossae similar to others described elsewhere, yet had strongly marked 

 individual features of its own. A case resembling this in some features 

 occui'red in an old emaciated female subject dissected at the end of the 

 last session in the Anatomy room of the Dublin University. This 

 subject showed a faiat superior ilio-eaecal pouch, whose floor was 

 formed by the layer of peritoneum at the inferior and left end of the root 

 of the mesentery, which was attached to the anterior surface of the psoas 

 muscle. There was no inferior ilio-c^cal fossa, and the mesenterio- 

 lum was slender, not bounding any ilio-caecal recess either above or 

 below it, nor was there a trace of a sub-caecal fossa. The descending 

 colon was veiy long, and, as is always the case under such circum- 

 stances, the end of the caecum was pushed well forwards, lying on the 

 anterior wall of the abdomen, the fundus of the caecum being well 

 tuimed forwards, and the peritoneal covering of this part of the large 

 intestine was exceedingly imperfect, the serous membrane passing as a 

 tense lamina from the sides of the caecum to the sides of the abdominal 

 wall. The ascending colon on the level of the crest of the ilium was 

 displaced backwards in a knuckle-like fold, to such a depth that the 

 middle part was quite buried in a backwards and inwards-reaching sac. 



* Antea, p. 79. 



