310 GOLGI BODIES ETC. 



Acid violet may often be employed in place of methyl green 

 particularly in the study of the hypophysis (Bailey, Jour. Med. 

 Res., 1920, xlii, 353). The mixture is : ^ 



Acid violet. . . . . .1 grm. 



10 per cent, sulphuric acid , . . 2 — 5 drops. 

 Aq. dest 100 c.c. 



The acid should be added drop by drop until the stain reaches 

 the desired intensity. 



702. Schridde's Method for Mitochondria, modified {Ergeb. 

 Anat. u. E. Merk. Bonnet, xx. 1911). Fix in this mixture : 

 formol (1 part), Miiller (9 parts), for two days ; then place in 

 Miiller, two to four days ; then 2 per cent. OSO4, for two days. 

 Wash overnight, dehydrate, clear in xylol, cut paraffin sections 

 5 fi. Stain as follows : iron alum hot for a quarter of an hour, 

 then ha^matoxylin hot, a quarter of an hour. Differentiate in 

 alum in the cold. This has the advantage over pure formol- 

 chrome techniques in that the introduction of the OSO4 preserves 

 fat * , recommended by Duesbefg. With this mordanting it 

 should be possible to stain either as for Altmann, Bensley-Cowdry, 

 Champy-Kull, or Benda. 



This method has been found by us to be one of the most useful 

 and reliable for mammalian and bird tissues. We find it an 

 advantage to bleach sections with 20 parts of HgOg in 80 parts 

 of absolute alcohol. The HoOg must be kept in an ice safe, 

 because if kept at room temperature it soon loses its oxygen. 

 After bleaching, Schridde material stains well by the hot alum 

 haematoxylin method. 



Levi, G. (Arch.f. Zellf., Bd. xi), ovary of mammals. 

 10 c.c. . 2-5 per cent. KgCrgO^. 



10 ,, .5 per cent, sublimate containing 2 c.c. of formol. 

 2 „ .2 per cent. OSO4. 

 Leave for three or four days. Wash out well in running water. Stain 

 in Regaud, Benda, etc. 



703. A. H. Drew's Formol-Chrome-Haematoxylin Method f 



{Journ. R. Micr. Soc., 1920). This method is used for demon- 

 strating rod-like bodies in the cytoplasm of plant cells. These 

 rods were, but are not now, supposed to be the homologue of the 

 Golgi apparatus of animal cells. The method will undoubtedly be 

 useful for studying animal tissues. 1. Fix plant root tips, etc., for 

 twenty-four hours in a mixture of formol, 20 c.c. ; cobalt nitrate, 

 2 grm. ; sodium chloride, 0-8 grm. ; water to 100 c.c. (preferably 

 at temperature of 37° C). 2. Soak fixed tissues in gum-syrup 

 for at least an hour, and cut sections on freezing microtome. 



* See warning' in § 691. 



t Grasse {A. Zool. Exper., 1926) attributes this to Luelmo, 1923. 

 For Protozoa you leave out steps 2 and 3. 



