PRACTICAL DIRECTIONS. 45^ 



IV. The pharynx (p. 231). Remove the large lymphatic gland 

 between the atlantal transverse process and the larynx. Clean the 

 outer surface of the pharynx. Dissect the muscles of the i)harynx 

 (p. 232) as follows : 



((/) The inferior constrictor (Fig. 96, ^). 

 [6) 'i"he middle constrictor (Fig. g6,j). 



(c) The glossopharyngeus (Fig. 96, i). 



(d) The stylopharyngeus (Fig. 96, /). 



The superior constrictor cannot well be seen at this point; it will 

 be examined later. 



Disarticulate the cranial cornu of the hyoid from the bulla 

 tympani and make an incision the length of the lateral wall of the 

 j)harynx so as to expose its cavity; study. Examine its opening into 

 the mouth-cavity and study the general description (p. 231). Find 

 and study the soft palate (p. 230). Dissect the tensor and levator 

 palatini muscles (p. 230, and Fig. 66, d and e, p. 112), using, if 

 necessary, the specimen on which the other muscles were dissected. 

 Then slit the soft palate lengthwise at one side of the median line to 

 expose the. nasopharynx (p. 231). Bring the choanas into view by 

 use of a bit of mirror-glass. Pass a bristle into the narcs and out at 

 the choanal. Pass a bristle through the Eustachian tube into the 

 middle ear. 



V. Gisophagus (p. 234). After completing the study of the 

 pharynx, leave the larynx and lungs in position and by displacing 

 them toward the right follow the oesophagus to its termination. 

 Open it to see the folds of the mucosa. 



VI. Cut through the duodenum at its distal end and through the 

 duodenal mesentery so as to separate the stomach and duodenum, 

 with the liver, pancreas, and spleen, from the remainder of the 

 alimentary canal. Float the parts in a dish of water. 



VII. Study the stomach (p. 234, and Fig. 97). Cut out the 

 ventral wall of the stomach and wash it out, so as to study its cavity, 

 and then continue the cut so as to expose the pyloric valve (p 235). 



VIII. Study the duodenum (p. 236). Cut away the ventral 

 walls of the duodenum far enough to expose the ampulla of Vater. 



IX. Study the liver (p. 239, and Figs. 100 and loi). Expose 

 the hepatic duct of the left lateral lobe near its entrance into the 

 lobe, and follow it so as to expose it fully. If necessary, prick it and 

 inllate with blowpipe in order to follow it. Then ex})ose the cystic 

 duct and other hepatic ducts and follow them to or from the common 

 bile-duct. Trace the latter to the duodenum. If the air does not 

 enter any duct readily, it may be made to do so by manipulating the 

 duct so as to break up the precipitated bile which obstructs it. 



X. Study the pancreas (p. 241, and Fig. 102). Expose the 

 pancreatic duct near its entrance into the ampulla of Vater, by 

 removing the peritoneum from the pancreas just caudad of the end 

 of the common bile-duct, and by dissecting apart the pancreatic 

 lobules until the duct api)ears. (If possible, expose also the acces- 



