44 



PHYSIOLOGY OF FARM ANIMALS 



[CH. 



each villus is covered by a columnar epithelium resting ou a fine 

 basement membrane. This epithelium is continuous with that 

 lining tlie rest of the mucous membrane. Beneath the basement 

 membrane is a rich supp]}^ of blood vessels. 



circular muscles i ■ ' 



longitudinal muscles 



serous coat 



Fig. 27. Section through wall of duodenum (from Schafer.) 



