150 



THE ESSENTIALS OF HISTOLOGY 



intestine is closely beset are clavate or finger- shaped projections of the 

 mucous membrane, and are composed, like that, of lymphoid tissue and 

 covered with columnar epithelium (fig. 182). The characters of this 

 have been already described (Lesson VII.). Between and at the base 

 of the epithelium-cells many lymph-corpuscles occur. The epithelium 

 rests upon a basement-membrane formed of flattened cells. In the 

 middle of the villus is a lacteal vessel (c. I) which is somewhat 

 enlarged near its commencement. Surrounding this vessel are small 



FIG. 182. CROSS-SECTION OF A VILLUS OF THE CAT'S INTESTINE. 



e, columnar epithelium ; g, goblet eel', its mucus is seen partly exuded ; I, lymph-corpuscles 

 between the epithelium-cells ; 6, basement-membrane ; c, blood-capillaries ; m, section 

 of plain muscular fibres ; c. I, central lacteal. 



FIG. 183. MAGNIFIED VIEW OF THE BLOOD-VESSELS OF THE INTESTINAL VILLI. 



The drawing was taken from a preparation injected by Lieberklilm, and shows, belonging to 

 each villus, a small artery and vein with the intermediate capillary network. 



bundles of plain muscular tissue prolonged from the muscularis mucosae. 

 The network of blood -capillaries (fig. 183) lies for the most part near 

 the surface within the basement -membrane ; it is supplied with blood 

 by a small artery which joins the capillary network at the base of the 

 villus ; the corresponding vein generally arises nearer the extremity. 

 The lymphatics (lacteals) of the mucous membrane (fig. 184), after 



