THE STOMAGE. 385 



..1 Jw^^?^^^ disposition of the peritoneum varies but little in the different species tlie 



ri^, tht !^Tl'^''f^"°i''°'.T,'''^<^ '^ *'"^g^'=*t omentum. In the Ox, S' and 

 Goat this IS detached from the middle of the lower face of the rumen, and enveloiL tbo 

 right sac of that organ, fismg the fourth compartment to its great curvature! and then 

 passing upwards to become continuous with the mesentery. In the Dog and P^ li^ 

 ltT,erto.'°^',>f,f'°'';^ of the intestinal mass until near the pelvis ; then it ascends in 

 gathering on itself, and ultimately spreads over the colon : in the middle portion of the 

 great omentum there ai-e, consequently, four layers placed against each other. 



COMPAKISOIJ- OF THE ABDOMINAL CAVITY OF MAN WITH THAT OF ANIMALS. 



The abdominal cavity of Man is elongated vertically, and has an inferior cavitr 

 occupying the entrance to the pelvis. There is nothing particular to note in its disposi- 

 tion, the differences observed in it being allied to the external shape of the body The 

 peritoneum is spread over its parietes nearly in the same manner as in the Carnivora ■ 

 the great omentum is constituted by four layers, and covers the intestines like an apron .• 

 between its two laminas is the lesser cavity of the omentum, virtually m the adult. 



THE STOMACH. 



Tie stomach is a membranous sac comprised between the oesophagus 

 and. intestiaes, and in which are commenced the essential phenomena of 

 digestion. 



1. The Stomach in Solipeds. (Figs. 182, 183, 184, 185, 186.) 



Preparation. — In order to study the relations of this organ, it suffices to open the 

 abdomen and remove the intestinal mass in the following manner .-—Place the animal in 

 the first position, and very slightly inclined to the left side ; make an incision through 

 the inferior abdominal wall, or, still better, carry it away entirely by a circular incision, 

 taking care not to wound any part of the intestine. The entire viscera should then be 

 withdrawn from the abdominal cavity, and laid on tlie table which supports the subject ; 

 for this mass cannot be allowed to fall on the ground without risk of being pulled and 

 torn, either in thu intestine itself, or those parts which it is desired to preserve intact in 

 ihe alidomen. Incise the floating colon where it joins the rectum, and the duodenum 

 where it passes behind the gi'eat mesenteric artery ; the base of the cascum should now 

 be detached fi'om the sublumbar surface hy the rupture of the cellular tissue which 

 connects it to the right kidney and the pancreas; the cellular connection between the 

 latter gland and the terminal extremity of the fourth portion of the large colon should 

 also be broken ; after this, it is only necessary to divide the attachment of the mesenteric 

 bands to the sublumbar region, with the vessels contained between them. The intestinal 

 mass is then definitively expelled from the abdominal cavity. In this way it is possible to 

 expose, and conveniently prepare, not only the stomach, but also the spleen, liver, pancrea.s, 

 kidneys, ureters, etc. Nothing more remains than to make known the procedure to be 

 adopted in everting the stomach, in order to study its intciTial surface, or dissect its deep 

 musoular layer. It is recommended, first, to excise the stomach with at least three inches 

 of the cesopnagus, and eight inches of the duodenum, and cleanse the inteiior of the organ. 

 This may be done in several ways, but the following is the simplest :— a certain quantity 

 of water is introduced into the stomach by fixing the duodenum to a water-tap, the 

 right hand manipulating the organ while the left closes the duodenum to prevent the 

 escape of the liquid. The alimentary substances contained in it are in this way mixed 

 with the water, and may be expelled from the duodenum by pressing the stomach ; this 

 operation being repeated four or five times, thoroughly cleanses the cavity of the organ. 

 To evert the inner surface, it is only necessaiy to introduce by the duodenum a loop of 

 wire and make it pass through the oesophagus ; a strong waxed thread is fastened in 

 the loop and firmly fixed around the oesophagus, when, m pulhng back the wire, this 

 extremity is drawn towards the pylorus, and by carofnl traction the latteris so dilated 

 as to allow the passage of the cardiac end, and complete eversion of the stomach Inflation 

 will then give it its normal form and disposition ; with thi3 cUflerence, that the mucous 

 membrane is external, and the serous tunic internal. ■ , *. -^ ■ .:■ ■ vi * 



Lastlv to render the musoular layers of the stomach more evident, it is advisable to 

 plunge the organ into boHing water for some minutes, after which it should be put into 

 cold water If it is desired to study the external and middle layers, the stomach should 

 be inflated, audits serous covering removed by strips with forceps and the fingers ; if the 

 deep layer is to be examined, the mucous membrane must be removed by means of the 

 forceps and scalpel from a stomach previously everted. 



