1894.] MICROSCOPICAL JOURNAL. 317 



brush. Place on a slide, stain with picro-carmine, mount 

 in glycerine. 



2. — The foregoing preparation will show the reticu- 

 lated tissue freed from the flat cells that carpet it. The 

 following method will show the same tissue with the en- 

 dothelial cells. Insert the needle of a hypodermic sy- 

 ringe into a lymphatic gland of a dog, and gently inject 

 a one per cent solution of osmic acid. Put the gland in 

 water for 1 hour, follow^ by gum and by alcohol. Make 

 very thin sections and shake them for some time in a 

 bottle half filled with water. 



3. — Section parallel with the long axis of a gland 

 through the umbilicus (hilum). Harden by alcohol, im- 

 bed in gum, examine in glycerine, after staining by pi- 

 cro-carmine. To show the differences between the sin- 

 uses and the follicles, inject into a gland some Prussian 

 blue in aqueous solution. Fix by ammonia bichromate 

 and harden in gum and alcohol. Stain with haematoxy- 

 lin and mount in balsam. 



4. — The ganglionic blood vessels may be studied in the 

 rabbit or in the rat by injecting with the blue gelatine, 



LYMPHATIC VESSELS. 



The large lymphatic vessels should be studied in sec- 

 tions made by the method recommended for the arteries. 

 Those of small diameter can be observed with all their 

 details, (valves, muscular fibres, etc.), in the mesentery 

 of an animal without much fat. Spread on a slide a 

 shred of the mesentery upon which a one per cent solu- 

 tion of osmic acid should act for J an hour. Wash, stain 

 by picro-carmine for 3 or 4 hours, wash again ; examine 

 in balsam. 



(To be continued). 



Dr. Hauser. — A chair of Bacteriolog.y is to be established at 

 Erlangen and Dr. Hauser will probably occupy it. 



