170 ELEMENTARY PHYSIOLOGY. [XVI. 



a. The central cells forming a tube with very 

 small lumen. 



6. The comparatively rare ovoid cells outside 

 the central cells. 



5. From the pyloric end of the stomach prepare- 

 vertical sections and stain them with haema- 

 toxylin, compare these with the sections made 

 of the cardiac end. Note 



a. The greater thickness of the longitudinal 

 and circular muscular layers. 



6. The wider and longer mouths to the glands, 

 their more frequent branching and the 

 absence of ovoid cells (if the section passes 

 through the upper part of the pyloric region 

 a few ovoid -cells may be seen). The cells 

 below the mouths of the glands (pyloric 

 gland cells) resemble in general appearances 

 the central cells of the cardiac end of the 

 stomach. 



B. STRUCTURE OF THE OESOPHAGUS. 



1. Make transverse vertical sections from the lower 

 third of a rabbit's resophagus, which has been 

 hardened in potassium bichromate 1 p. c., and 

 compare them with the corresponding sections 

 of the stomach. Note the following points of 

 contrast : 



a. The external muscular layers contain striped 

 as well as unstriped muscular fibres ; sections 



