GOLGI BODIES ETC. 305 



cut from 4 to 8 /z, but we generally find 6 /x to be eonvenient. 

 Leave eight to ten hours in iron alum, tivelve to twenty hours in 

 hcematoxylin. The most convenient method is to leave all day in 

 alum, and overnight in ha^matoxylin, differentiating next morning. 

 This method gives a delicate and precise stain of the mitochondria 

 (and Golgi apparatus or nebenkern batonettes of male germ-cells 

 only), fatty yolk is black, while yolk is generally greenish-brown. 

 Especially recommended for germ-cells, and histology of Inverte- 

 brata, but with vertebrate tissues, and especially mamiualian 

 material (not embryos), it often gives poor results ; for such 

 material, Helly, Zenker, or Regaud's methods are indicated 

 (Gatenby, Qiiart. Journ. Micr. Set., 1919), or fix in salt Flemming 

 §47. 



Note that Flemniing-without-acetic acid is not a suitable fixative for 

 after-staining in Altmann's acid fuchsin. For this the material must be 

 washed in distilled water for a short time after fixation, and then 

 transferred to 3 per cent, bichromate of potash for three days ; or 

 the more elaborate mordanting as for Champy-Kull may be used (§ 695). 



694. Altmann's Acid Fuchsin and Picric Acid {Die Ele- 

 mentarorganismen, Leipzig, 1890). Fix twenty-four hours in 

 mixture of equal parts of 5 per cent, bichromate of potash and 

 2 per cent, osmic acid. Imbed in paraffin, stain sections on slide 

 for one minute over flame, with a solution of 20 grm. {sic) of 

 acid fuchsin in 100 c.c. of aniline oil-water *. Cool, and wash 

 out in a saturated alcoholic solution of picric acid diluted with 



2 volumes of water, heat being used as before to aid differentiation ; 

 blot, dip into 90 per cent, or absolute alcohol, xylol, balsam. 

 This method only stains granules which can be seen intra vitam ; 

 properly used it never produces artifacts, and Fischer's critique 

 is quite wrong {Fixirung Faerbung u. Bau des Protoplasmas). 

 Altmann's original method has been superseded more or less by 

 the following method of Champy-Kull. 



Both Murray and Gatenby found that the 20 grm. of acid fuchsin 

 would not dissolve in 100 c.c. of anilin oil-water ; only about 5 to 

 7 grm. would dissolve, and this quantity will make a perfectly efficient 

 solution. John Baker gets 12 per cent, to dissolve. Conn's specimen 

 up to 20 grm. 



■J. Baker and ]M. Thomas (Baker, Cyiological Technique, 1933) 

 propose the following modification : equal parts of 3 per cent, 

 biclu'omate of potassium and 2 per cent, osmium tetroxide. Fix 

 for four days, or for one day and post-clu-ome for three days in 



3 per cent, bichromate alone. Wash out overnight in running 

 water. Cut sections 5 /x or less. Add the acid fuchsin, heat with 

 Bunsen till it steams for one minute. Leave live minutes to cool. 

 Pour off, then distilled water, then flood with picric solution 



* Add oil to water till no more dissolves, shake vigorously, filter. 



