Study on the type of the cloacal epithelium in muscovy duck

The type of the cloacal epithelium of duck was studied by using histological techniques.The results showed that the cloacal epithelium of duck was stratified squamous epithelium.There was no goblet cell between epithelial cells, and no villus at the mucosal surface.The mucosal epithelium of rectum transforms into stratified squamous epithelium abruptly at the end of the rectum.The boundary line between rectum and cloaca was very distinct.