662 METHODS OF SPECIAL STAINING ETC. 



drop of concentrated alcoholic solution of cyanin to living materia] 

 and, after a time, enough water to precipitate the cyanin not 

 taken up. The cilia are at first pale blue, but after the addition of 

 water deep violet. 



Rapid killing with osmic acid vapour, 1 per cent, osmic acid, 

 1 per cent, chromic acid or iodine-potassium iodide solution is 

 essential. 



Zimmermann fixes a drop of suspension on a slide with osmic 

 vapour and allows it to dry. Add a drop of 20 per cent, aqueous 

 tannin and wash off with water after five minutes. Stain in 

 concentrated aqueous fuchsin, or, better, carbol-fuchsin. Wash 

 with water, dry and mount in balsam. Loeffler's flagella stain 

 (for bacteria) can be used for difficult cases. See also Hollande, 

 Arch. zool. exp. et gen., lix, 1920, p. 75. 



For algal and fungal zoospores add a drop or two of 1 per cent, 

 osmic acid to the water containing them and then a drop or two 

 of strong alcoholic solution of equal parts of fuchsin and methyl 

 violet. 



1327. Nucleoli. Zimmermann recommends fixation with con- 

 centrated alcoholic solution of corrosive sublimate and staining 

 by Altmann's acid fuchsin-alcoholic picric {Arch. Anat. Physiol., 

 Anat. Abt., 1889, p. 409), Zimmermann's acid fuchsin and acid 

 fuchsin-potassium bichromate methods or double staining with 

 acid fuchsin and Delafield's haematoxylin. 



Lenoir (C R. Soc. Biol., cix, 1932, p. 471) fixes Equisetum 

 sporangia in a formalin-acetic acid-chromium acetate mixture, 

 mordants in alcohol and HCl, stains with carbolated fuchsin D 

 and differentiates with a mixture of clove oil, absolute alcohol and 

 picric acid. The nucleolin is intensely stained to the exclusion of 

 reticular chromatin. 



Lenoir (C. R. Soc. Biol., cxviii, 1935, p. 1554) also recommends 

 fixation in Bouin-Duboscq-Brasil (Lenoir, C. R. Soc. Biol., ciii, 

 1930, p. 1258), followed by double staining with basic fuchsin and 

 malachite green (Lenoir, C. R. Soc. Biol., civ, 1930, p. 1282). 

 The chromosomes are red, the nucleolus green. The stain fades 

 in time. 



Dannehl and Ziegenspeck {Bot. Archiv., xxv, 1929, p. 243) 

 used triacid staining for distinguishing nucleoli from chromosomes 

 at all stages. 



See also § 646 and Zirkle, Bot. Gaz., Ixxxvi, 1928, p. 402. 



1328. Other Cell Organs. Centrosomes and blepharoplasts are 

 very responsive to osmic acid, failing to be visible following chrom- 

 acetic fixation without it. Polar caps and spindle fibres are less 

 distinct following fixatives where the osmic is large in amount. 

 The osmic acid should be reduced as far as possible in Flemming 

 fluids used for this purpose, but if too little in amount the 

 cytoplasm appears as a mass of coarse vacuoles. 



