xxxviii.] FRESH TISSUES. 403 



in these cells are stained by a fluid composed of 100 cc. water, 50 

 cc. absolute alcohol saturated with dahlia, 10-12.5 cc. glacial acetic 

 acid. The leucocytes are stained blue, while the granules have 

 what Ehrlich calls a metachromic red-violet tint. They correspond 

 to Ehrlich's y-granulations, and have been specially investigated by 

 Westphal (loc. cit., p. i 7). 



The 8-granulations occur especially in the mononuclear leucocytes 

 of human blood. They are stained by basic dyes. 



The e-granulations, or neutrophile granules, occur in the poly- 

 nucleated elements of human blood. They are stained only by 

 neutral dyes, e.g., acid-fuchsin and methyl-blue. Ehrlich classifies 

 dyes as acidophile, e.g., eosin, aurantia, and indulin ; neutrophile^ 

 e.g., acid-fuchsin or fuchsin-S, methyl-blue ; lasophile, e.g., dahlia, 

 gentian-violet, fuchsin. 



Ehrlich also calls granules which attract acid dyes " oxyphile " 

 a term adopted by Wright and Bruce, * whose method is described 

 below. According to the latter observers, the nucleus of the leuco- 

 cyte is invariably basophile, while the granules of normal leucocytes 

 are oxyphile. 



Staining of Oxyphilous or Eosinophilous Granules. Cover- 

 glass preparations are fixed either by dry heat (Ehrlich's method) 

 or by chemical reagents (osmic acid, HgCl 2 ). 



Eloat the cover-glass on a i per cent, watery solution of eosin 

 (J i min.). If it be desired to stain even more rapidly, add a trace 

 of acetic acid to the fluid, when the preparation rapidly becomes 

 over-stained. The surplus dye can be removed from all parts of the 

 cells, except the oxyphile or eosinophilous granules, by dipping the 

 cover-glass into a very dilute solution of sodic carbonate. 



Basophilous Granules. These are best stained with Loeffler's 

 methylene-blue, which stains all basophilous elements, e.g., nuclei 

 and basophile granules. It may dissolve out oxyphilous granules. 

 If the specimen has been already stained with eosin (the excess 

 extracted by weak alkali), then only a second or so is required to 

 stain with methylene-blue. Thus with care it is possible to stain 

 the oxyphile and basophile elements of the leucocyte. 



These observers deny the existence of so-called neutrophile 

 granules. They believe them to be really oxyphilous in their 

 behaviour to stains. 



32. Stained Leucocytes. Either one's own blood or the blood of 

 an animal, or the leucocytes of lymph-glands, may be used. Use the 

 dry cover-glass method, passing the cover-glass three times through 

 the flame of a Bunsen-burner before staining. Excellent prepara- 

 tions of the nuclei stained blue are obtained by methylene-blue 



1 Brit. Mcd. Jour., Feb. 1893. 



