VI.] CILIATED EPITHELIUM. 139 



9. Ciliated Epithelium (|_ and H). Mount a vertical section of 

 the respiratory mucous membrane of the septum of the nose of a cat 

 or other animal. The tissue has been previously hardened in Miiller's 

 fluid, or in chromic and spirit fluid, or, what is better, a saturated 

 watery solution of corrosive sublimate for two or three hours. In the 

 last case, every trace of the metallic salt must be removed by prolonged 

 and frequent washing with alcohol. Stain the section with logwood 

 and mount it in balsam ; or picro-carmine can be used. 



(a.) Observe several layers of cells (fig. 102), but only the super- 

 ficial layer of cells is furnished with cilia, which are placed on a 

 clear disc on the free end of the cell. Notice the shape of the cells 

 in the subjacent layers. Those of the lowest layers are nearly 

 spherical, while in the intermediate layers they are more elongated, 



Disc. 



Intermediate FIG. 103. Various Forms of 

 Forms. Goblet-Cells from the Mucous 



Membrane of the Hard Palate 

 Deepest Layer aiul (Esophagus of the Frog, 

 of Cells One of the cells shows mucus 



exuding from the open mouth 

 of the cell. Dilute alcohol 

 FIG. I02.-V.S. of Ciliated Epithelium. and picro-carmine, x 300. 



and are described as battledore-cells, arranged in between the others. 

 They replace the ciliated cells when the latter are shed. 



10. Isolated Goblet-Cells (H). These are readily obtained by 

 macerating the stomach of a frog in dilute alcohol for twenty-four 

 hours. Scrape the surface and diffuse the cells in glycerine. They 

 may be stained with picro-carmine, or they may be diffused in salt 

 solution and stained with methyl-violet, but the latter preparation 

 cannot be preserved in glycerine. Numerous goblet-cells will be 

 found in 7. 



(a.) Observe the isolated cells (fig. 103). Each cell is filled for 

 more than three-fourths of its capacity with mucus, while at the 

 lower tapering end there is a nucleus embedded in a small quantity 

 of protoplasm. Sometimes a plug of mucus may be seen exuding 

 from the, open mouth of a cell. 



(l>.) With a high power the interior of the upper part of these 

 cells may be seen to contain a fine network of fibrils. In the meshes 

 is a substance, mucigen, and when this is acted on by water it yields 

 mucin. In a certain sense these bodies are unicellular muciparous 

 glands. 



