TEST REACTIONS. Ill 



7. Remove excess of glycerin and mount in glycerin-gelatin, 

 as directed under the latter medium. 



8. Enclose the cover glass with a ring of cement (asphaltum, 

 Brunswick black, etc.) . 



C. MORE IMPORTANT TEST REACTIONS OF THE PARTS OF VEGE- 

 TABLE CELLS. (BOWER'S Practical Botany.) 



CELLULOSE CELL-WALLS 



1. Colored faintly yellow by iodine. 



2. Swollen and ultimately dissolved by sulphuric acid. 



3. Colored blue with iodine and sulphuric acid. 



4. Colored blue or violet with chlor-zinc-iodine. 



5. Stained by solutions of carmine or hsematoxylin, by 



methylene-blue and in various degrees by other aniline 

 colors. 



LlGNIFIED CELL-WALLS 



1. Colored distinctly yellow by iodine and by chlor-zinc- 



iodine, but in case of bast fibres the tint may vary to 

 sherry-brown or even pink. 



2. Colored brown and swollen by iodine and sulphuric acid. 



3. Colored bright yellow by acidulated solution of aniline 



sulphate. 



4. Colored red with acid solution of phloroglucin. 



5. Stained slightly or not at all by solutions of carmine and 



hsematoxylin, but readily by aniline colors. 



CUTICULARIZED OR CORKY CELL-WALLS 



1. Yellow by iodine. 



2. Yellow or brown by chlor-zinc-iodine. 



3. Yellow by strong potash; on gradually warming (without 



boiling) bright yellow. 



4. Resist action of sulphuric acid, retaining their clearly- 



marked outlines. 



5. Are not stained by solutions of carmine or haematoxylin, 



but are colored by aniline stains. 

 MUCILAGINOUS WALLS Resemble cellulose in many reactions. 



1. Swell with water and to a greater extent with potash. 



2. Do not stain with iodine. 



3. Stain red with Hanstein's aniline-violet, blue with methyl- 



ene-blue. 

 CALCIUM OXALATE Occurs in cells in form of crystals. 



1. Insoluble in acetic acid. 



2. Soluble without evolution of gas in nitric or hydrochloric 



acids. 



3. Soluble in sulphuric acid, with formation of fresh crys- 



tals of calcium sulphate if only small bulk of fluid be 

 present. 



4. Are not stained with iodine. 



