116 DIGESTION 



Note the relative length and diameter of its various parts and 

 determine the ratio of its length to the length of body. 1 



g) Open stomach along its greater curvature : 



Note character of mucous membrane. 



Examine under water the surface of lining membrane with 

 microscope. 



h) Remove liver: 



Note its general form and relation to body as a whole, to 

 stomach, and to intestine, with special reference to veins and 

 bile duct. 



Scrape its cut surface and examine cells in normal salt solu- 

 tion under microscope. 



Find gall-bladder and trace out its ducts. 



i) Cut out piece of intestine (also cf calf or pig), wash inner 

 surface gently with normal salt solution, and examine in the 

 solution with a hand lens. 



j) Place pieces of small intestine in 50 per cent alcohol for 

 24 hours. Then open and examine villi under water with a 

 hand lens. 



Digestion 



Materials and apparatus : Sugar ; salt ; raisins, grapes, cran- 

 berries and other fresh fruits, with skins and stems uninjured; 

 corn or arrowroot starch ; olive oil ; blood fibrin either fresh or 

 dried and softened in warm' water, or egg albumin coagulated 

 by slowly pouring white of egg, which has been cut up with 

 scissors and forced through cheese cloth, into boiling water 

 acidulated with vinegar; meat juice; milk; bile of pig or other 

 animal, obtained from butcher ; glycerole pepsin, Parke, Davis & 

 Co. ; pancreatic extract made by dissolving in 2 oz. warm water, 

 15 grs. dry extract obtained from druggist; saliva collected by 

 chewing paraffin or a piece of rubber and filtered ; hydrochloric 

 acid, 2 per cent solution made by adding 1 teaspoonful com- 

 mercial hydrochloric acid to 1 qt. water; sodic hydrate solu- 

 tion; copper sulphate solution; water bath for holding test 

 tubes (a deep tin containing a wire test tube rack, nearly 



1 It must be remembered that the rabbit is herbivorous and 

 therefore has an alimentary tract quite different in certain 

 particulars from that of man. The alimentary canal of a cat or 

 dog more nearly resembles the human. 



