STOMACH. 67 



striped muscular fibres. Observe the relation of the outer and inner cells, and notice 

 the small lumen of the gland. (Indicate the appearance of transverse sections of the tubes in 

 PL XIII., Fig. 4.) 



Aniline Blue. Stain a section with a watery solution of aniline blue. Mount it in glycerine 

 or dammar. The peptic cells are most deeply stained. 



PYLORIC END OF STOMACH. 



EXAMINATION. Observe the mucous coat, containing glands (mucous) which branch 

 frequently, and do not contain any large ovoid cells. The gland-ducts are relatively long, 

 and two or three tubes open into a short neck. The gland-tube is lined by the same kind of 

 epithelium throughout. Notice transverse and oblique sections of the gland at the lower 

 part of the mucous membrane. Here and there, near the base of the gland, detached 

 patches of adenoid tissue may be seen. (Indicate the general arrangement in PL XIII., Fig. 5.) 



Take another section, stain it with carmine, and mount in Farrant's solution. Notice the 

 same general arrangement as above. Observe that the glands are lined throughout with 

 columnar epithelium. Study a transverse section, and note the basement-membrane of a 

 gland. Notice a few leucocytes lying near the bases of the glands. 



Isolation of the Gastric Glands. PREPARATION. Place small pieces of the mucous 

 membrane of the stomach of a rabbit in five per cent, ammonium chromate for three days. 

 Wash away the colouring matter from a small piece of the membrane, and place it in picro- 

 carmine solution for twenty-four hours ; tease a small piece in glycerine. This method shows 

 the shape and general characters of the glands, and their cellular contents, the ovoid cells 

 being specially distinct. The nucleus is stained of a bright red, and a beautiful intra-cellular 

 plexus of fibrils is revealed. Note also the basement-membranes of the gland-tubes. (Indicate 

 the cells in the gland-tube in PL XIII., Fig. 3.) 



The osmic acid preparations show the peptic cells very well. They are more deeply 

 stained than the other cells, and hence they stand out more clearly. 



Blood-vessels of the Stomach. PREPARATION. Inject the blood-vessels of the stomach of a 

 cat or dog through the gastro-duodenal artery with a carmine gelatine mass (p. li), and place 

 the organ in alcohol. Make vertical sections and stain them with logwood and mount in 

 dammar. If a blue mass be used stain the sections with carmine. 



EXAMINATION (L). Observe the vascularity of the mucous membrane ; sections of the 

 large vessels will be found in the submucous coat ; and from these capillaries proceed upwards 

 between the glands, and form a capillary plexus round them. The veins rise near the surface, 

 and run downwards towards the submucous coat. 



DUODENUM. SMALL INTESTINE. 



PREPARATION. Wash out the contents of the duodenum of a dog or cat with a stream 

 of salt solution, and place pieces one inch long in chromic and spirit fluid for two weeks. If 

 the duodenum of a pig can be obtained, it is to be preferred. Place similar pieces of the small 

 intestine some with, others without a Peyer's patch, in the same hardening fluid for the same 

 time. Complete the hardening in alcohol. Make transverse sections. Stain a section of the 



