Studies on the histogenesis of the tunica mucosa of the small and large intestines of the camel (Camelus dromedarius). II. Histogenesis of the colonic mucosa.

The colon is at first a simple tube, and its mucosa has a smooth luminal surface, surrounding a previous lumen. At the 150 mm stage the mucosa is thrown into a number of stout projections, each has a vascularized mesenchymal core and an epithelial cloth. These projections are in turn split into finger-like villi by transverse furrows. The villi reach their maximal length at the 260 mm stage and then gradually degenerate and slough into the lumen. The villi were completely disappeared at the 730 mm stage. The colonic glands were firstly observed at the 200 mm stage as downgrowths of the intervillous epithelium and they increase in number by dichotomous division of their bases. The Lamina muscularis mucosae is completely constructed at the 730 mm stage.