2 80 



PRACTICAL HISTOLOGY. 



[xxv. 



gland perforates the muscularis mucosse, passes up between the 



intestinal glands, and opens 

 on the free surface at the 

 bases of the villi. It has a 

 distinct lumen, and is lined 

 by low cubical epithelium. 



' 10. Fresh Villus. Pre- 

 ferably that of a mouse. 

 Examine in normal saline. 



LARGE INTESTINE. 



Methods. Prepare it in 

 the same way as the small 

 intestine, .and make vertical 

 transverse sections. The 

 details of the structure will 

 necessarily vary with the 

 animal used, but perhaps the 

 cat is as convenient an 

 animal as any to employ. 

 I can strongly recommend 

 Flemming's fluid. Sections 

 to be stained with safranin. 



11. T.S. Large Intestine (fig. 270). As the large intestine is 

 wide, it is necessary in making the section to select a portion of the 

 great gut which shows the longitudinal coat. In man, the coat 

 is not a continuous one, the longitudinal fibres being grouped for 

 the most part into three flat bands of fibres. 



(L) Beginning from without inwards, observe four coats. In 

 the muscular coat, note the peculiarities of the longitudinal coat 

 and the thick well-marked continuous circular coat. There is 

 nothing special about the .submucous coat, unless it be the exist- 

 ence of solitary follicles, which, however, arc not confined to 

 the large intestine. The mucous coat is characterised by negative 

 characters. There are no villi. It may exhibit folds, into each 

 of which there runs a projection of the submucous coat. 

 Lioherkiilm's glands, cut vertically, and some of them obliquely or 

 horizontally. 



(H) In the mucous coat the glands of Lieberkiihn, larger than 

 those of the small intestine, and lined by cells protoplasm cells 

 with nuclei near their attached ends. Amongst them are very 

 many goblet-cells (fig. 271). 



Serous coat. 



FIG. 269. V.S. Duodenum of Cat. c, I. Circular 

 and longitudinal layers of muscle; Lg. Lieber- 

 kiihn's glands ; JSg. Bruuner's glands ; g. 

 Ganglion-cells ; v, Villi. 



