METHODS FOIi, INVEIMEBBATES. . 481 



Trypanosomes intra vitam by adding a drop of concentrated 

 solution of neutral red to the edge of a drop of blood spread 

 between slide and cover. 



925. Flagellata. — Lauteebgen {Zeit. wins. Zool., lix, 1895, 

 p. 170) fixes Geratium for about ten minutes in liquid of 

 Flemming, puts into alcohol for twenty-four hours, brings 

 back into water, bleaches if necessary with hydrogen per- 

 oxide, and stains with picrocarmine or Delafield's hsematoxylin. 

 He also imbeds in paraffin, § 921, and stains sections with 

 iron heematoxylin. 



Zachaeias {Zool. Anz., xxii, 1899, p. 72) fixes TJroglena, 

 etc., with a mixture of 2 vols, saturated aqueous solution of 

 boracic acid and 3 of saturated sublimate. 



926. Stains for Flagella. — The Romanowsky stain will give 

 a red stain of the flagella of some forms. 



The method of Lopflee [Centralbl. BaJeteriol., vi, 1889, p. 

 209 ; vii, 1890, p. 625 ; Zeit. iviss. Mik., vi, 1889, p. 359 ; vii, 

 3, 1890, p. 368; Jouni. Roy. Mic. Soc, 1889, p. 711; 1890, 

 p. 678) is as follows. To 10 c.c. of a 20 per cent, solution 

 of tannin are added 5 c.c. of cold saturated solution of ferrous 

 sulphate and 1 c.c. of (either aqueous or alcoholic) solution 

 of fuchsin, methyl violet, or "Wollschwarz." Cover-glass 

 preparations are made and fixed in a flame in the usual way, 

 special care being taken not to over-heat. Whilst still warm 

 the preparation is treated with mordant (i. e. the above-des- 

 cribed mixture), and is heated for half a minute, until the 

 liquid begins to vaporise, after which it is washed in distilled 

 water and then in alcohol. It is then treated in a similar 

 manner with the stain, which consists of a saturated solution 

 of fuchsin in anilin water (p. 177), the solution being pre- 

 ferably neutralised to the point of precipitation by cautious 

 addition of O'l per cent, soda solution. 



See also Liebetanz, Arch. Protistenh., xix, 1910, p. 23. 



BuNGE {Joiirii. Hoy. Mic. 8oc., 1894, p. 640 ; Zeit. wiss. Mile, 

 xiii, 1896, p. 96) makes the mordant by mixing three parts 

 of the tannin solution with I of liquor ferri sesquichlorati 

 diluted twentyfold with water, and lets the mixture ripen 

 for some days exposed to the air, or [Journ., 1895, pp. 129, 

 248) adds to it a few drops of hydrogen peroxide, until it 



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