EHRLICH'S " MASTZELLEN." 343 



hours in turpentine. It is dissolved also in xylol, ether and 

 kreasote. Flemming finds that very good demonstration- 

 preparations may be made by treating fatty tissue with 

 chromo-aceto-osmic acid, staining with safranin or gentian, 

 and then treating for a few hours with turpentine until all the 

 fat is dissolved. The optical hindrance caused by the high 

 refraction of the fat being thus eliminated, nuclei and cyto- 

 plasm may be studied to far greater advantage than in the 

 usual preparations. 



684. Granule Cells (" Plasmazellen " and " Mastzellen "). In 

 1874, there were described by WALDEYEE (Arch. f. mik. Anat., Bd. xi) 

 certain special cells existing between the bundles of connective tissue, besides 

 the flat cells, and lymphatic and fat cells. They are large round cells con- 

 taining large granules ; Waldeyer called them plasma cells (" Plasmazellen"). 

 Later on, EHELICH (ibid., xiii, 1877) distinguished in the same tissue and in 

 other places certain cells containing large granules, which have a superficial 

 resemblance to Waldeyer's plasma cells, but which differ from them in 

 staining reaction (Verhandl. Berl. Physiol. Ges., January 17, 1879 : Reichert 

 u. Du Bois Raymond's Arch., 1879, p. 166). Ehrlich named these food 

 cells (" Mastzellen "), intending to express thereby the opinion that these cells 

 are derived from fixed connective tissue cells by a transformation brought 

 about by exalted nutrition. 



It is a pretty general character of these elements, that they take the stain 

 of anilin colours and retain it on treatment with alcohol with greater energy 

 than other tissue cells. And further (at least so far as regards the true 

 Mastzellen of Ehrlich) that in successful preparations they show the nucleus 

 unstained, the general mass of cytoplasm unstained or but slightly coloured, 

 and, in the cytoplasm, the characteristic granules very intensely stained. 



685. EHELICH'S " Mastzellen " (Arch.f. mik. Anat., 1876, p. 

 263). First method. Stain with neutral dahlia, and wash 

 out with acidified water, and mount as directed, supra, 103. 

 If there be any Mastzellen in the preparation they will be 

 brought out by the superior energy with which they take the 

 stain. 



Second method. It may be desirable to obtain a specific stain 

 of the plasma-cells alone, which may be done as follows : 



The tissues must first be well hardened in strong alcohol 

 (chromic acid and its salts must be avoided). They are then 

 placed for at least twelve hours in a staining fluid composed 

 of 



Absolute alcohol .... 50 c.c. 



Aqua 100 c.c. 



Acid. acet. glacial . 12^ c.c. 



