LESSON XVII. 

 INTESTINE. BILE. PANCREATIC JUICE. 



A. Steuctuee of Intestine. 



The outer coats of the intestine have the same general 

 characters as those of the stomach (Lesson xvi. A, § 1, 

 a — d), except that there is no oblique muscular layer. 



1. Prepare vertical sections of a cat's or dog's small 

 intestine hardened in chromic acid '2 p. c. (cp. 

 p. 33 F § 2). Stain with haematoxylin (the 

 tissue may be stained before sections are made 

 by placing it in dilute haematoxylin for a day). 

 Observe in the mucous coat 



a. The projections of the mucous membrane, or 

 villi; either extended and long, or contracted 

 and short with the surface thrown into folds. 

 Note 



a. The epithelium, consisting of rather long 

 columnar cells, each with a clear free 

 border more or less distinctly striated 

 with vertical lines, rather granular cell- 

 substance, and oval nucleus placed at 

 about the lower third of the cell; the 



