SECTION THREE 



Technique: 



1. Place a small amount of pollen on the centre of a slide. 



2. Wash by dropping on 70% alcohol to remove any adhering 

 oils and resins. 



Note: The alcohol will spread out and evaporate leaving a ring 

 of sludge, which should he removed with a piece of tissue paper 

 moistened with alcohol. 



3. Repeat this process until no more sludge comes out. 



4. Wash finally with 70% alcohol, and just before the last drop 

 of alcohol evaporates completely, place 2 drops of hot stained 

 glycerine jelly on the pollen and stir gently with a needle to ensure 

 even distribution. 



5. Cover with a coverslip, keeping the jelly under the coverslip 

 hot by heating gently with a bunsen flame. 



Note: Excessive heating will rupture many of the pollen grains. 



6. Remove the flame ; take off the coverslip and replace it with 

 a clean, flamed coverslip. 



7. Allow the sUde to cool ; then store in a cool place. 



Results: 



''Functional" pollen grains are fully expanded; exine and 

 intine are stained green ; cytoplasm red. Aborted grains are either 

 shrunken and stained green, or expanded in varying degrees 

 depending on the amount of non-autolysed cytoplasm present at 

 the time of mounting, and stained a mottled, reticulate red. 



Notes: The intensity of the Phloxin stain increases on standing, 

 whereas the action of the methyl green is practically instantaneous. 

 Preparations retain their brilliancy for about a year. 



Reference: Owczarzak, Alfred (1952), Stain Tech., 27, no. 5, p. 249. 



PHLOROGLUCINOL 



An extremely sensitive test for lignin, particularly suitable 



for hydrophytes 



Solution required: 

 Phloroglucinol 1% in 70% alcohol. 



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