1895.] MICROSCOPICAL JOURNAL. 239 



mucous membrane measuring about 1 c. in the I alcohol. 

 In twenty-four hours scrape the surface and spread the 

 result in a drop of the i alcohol ; stain with picro-car- 

 mine and cover after partly drying. After examining 

 the cells in the staining fluid, let glycerine run under 

 the cover so as to penetrate the cells very slowly. 



Sections.— After fixing by osmic acid (1 per cent) 

 1 mm, square of the mucous membrane, in 24hours wash 

 carefully (12 hours), harden in gum and alcohol, section, 

 stain in alum carmine, mount in glycerine. 



THE LARYNX. 



This presents a frame-work, ligaments, muscles and 

 a mucous membrane. The study of the frame-work 

 needs no other technique than that described for cartil- 

 aginous tissue. The same may be said of the muscles 

 and the ligaments. The mucous membrane will there- 

 fore exclusively occupy us. 



Take the membrane from the pharynx of an animal 

 just killed; do not allow it to dry. If the larynx of a 

 man can be obtained in half an hour or even one hour 

 after death, do not allow the opportunity to escape, as 

 the mucous membrane is a most remarkable object for 

 study. 



Dissociatio7i of the epithelial cells may be accomplished 

 after maceration in the I alcohol, following the tech- 

 nique described for the olfactory epithelium. 



Sectio7is. — Make them perpendicular to the surface. 

 For a fixative use alcohol, osmic acid or ammonia bi- 

 chromate. Harden in gum and alcohol, stain in alum 

 carmine if osmic acid is used, picro-carmine after alco- 

 hol and ha;matoxylin after bichromate. 



For the study of the trachea and the bronchia use the 

 preceding methods. 



(To he continued). 



