284 PRACTICAL HISTOLOGY. [XXV. 



The mucus in the fresh goblet-cells occurs in the form of granules. This is 

 best seen in a fresh preparation teased without the addition of any fluid, or at 

 most in Miiller's fluid. In sections fixed in Flemming's fluid and stained with 

 safranin, the goblet-cells are reddish. The network in these cells may be 

 stained with Bismarck-brown. 



According to Bizzozero, the epithelial investment of the villi is not renewed 

 by the proliferation of the cells covering it ; but by the proliferation and 

 upward growth of the cells lining Lieberkuhn's follicles. 



18. Terminations of Nerves in Stomach and Intestine. Besides the gold- 

 chloride method (Drasch, 1 nerves of the duodenum), and the methylene-blue 

 methods as used by Aronstein, 2 Golgi's silver method has been recently applied 

 by Erik M tiller 3 for this purpose. The method used was Golgi's "rapid 

 method" (Lesson XXX.), i.e., osmico-bichromate solution and subsequent 

 staining with silver nitrate. The nerve- fibres become black, and numerous 

 communications are found to exist between the plexuses of Auerbach and 

 Meissner. A very large number of nerve-fibrils enter the villi, and are dis- 

 tributed in them, reaching to the cylindrical epithelium covering them. They 

 end free and have not b.een seen to end in or between the cylindrical cells. 

 Some end in the smooth muscular fibres of the villi. Other fibrils surround 

 the gland tubes. It is said that branched cells, like nerve-cells, lie in the villi 

 (R. y CayaT). 



19. Methylene-Blue. Immediately after death inject into the thoracic 

 aorta of a guinea-pig or rabbit the following fluid: I gram methylene-blue 

 BX in 300 cc. normal saline. Open the abdomen and expose the gut to the 

 air for 2-3 hours. Place a thin piece of the wall of the small intestine in 

 picrin-glycerine of S. Mayer (p. 192) and search for the red dish- stained nerve 

 plexus (S. Mayer). 



If a piece of the gut be teased in picrin-glycerine, it is easy to isolate blood- 

 vessels with their nerves. It is to be noted that methylene-blue not only 

 stains the axis-cylinders of nerves, but also the cement of epithelial cells, so 

 that in some respects it acts like silver nitrate. 



20. Vermiform Appendix (Rabbit}. Fix in Flemming's fluid, Fol's solution, 

 or absolute alcohol. 



A. For Mitosis. (i.) Stain the sections (5-10 mins. ) in 



Gentian-violet ..... i gram. 



Absolute alcohol . . . . 15 cc. 



Aniline oil . . . . . 3 ,, 



Water 80 ,, 



(2.) Wash in absolute alcohol. (3.) Immerse (30-40 sees.) in i per cent, chromic 

 acid. (4.) Again absolute alcohol (30-40 sees.); and (5.) in chromic acid. 

 Then in absolute alcohol to remove all surplus dye. Balsam. In this way 

 the chromatin of the nuclei is stained. 



B. For Micro- Organisms. Stain as above in (i). (2.) Absolute alcohol 

 (5 sees.). (3.) Weak iodine solution, i.e., Gram's method (p. 105) (2 mins.). 

 (4.) Then alternately chromic acid and alcohol as above. Balsam (Bizzozero). 

 The secret of getting good preparations is to wash them well in absolute 

 alcohol until all surplus dye is removed. 



21. 'Peyer's Patches and Phagocytosis. (a.) Harden a Peyer's patch 

 (rabbit) in absolute alcohol, cut sections in paraffin, and stain them in alum- 

 carmine, or in addition with gentian-violet by Gram's method (p. 284) 



1 Sitzb. d. k. Akad. d. Wissenscli., Bd. 81, iii. Abth., Wien, 1880. 



2 Aunt. Anzeigcr, Bd. ii., 1887. 



3 Archivf. mik. Anat., Bd. xl., 1892. 



