1895.] MICROSCOPICAL JOURNAL. 349 



and noticed to my surprise that they act in their totality 

 like an acid tissue. With the ordinary nuclei, as is well 

 known, the acid media react most markedly upon cliro- 

 matine threads and cell hodies only, and in such a 

 prominent manner that these structures are capable in 

 the presence of acids of retaining the previously-ahsorbed 

 basic colors, and therefore ]_)ermit themselves to be 

 tinctorially isolated by acids. The great mass of the 

 cell, above all the cell juice, on the other hand, reacts 

 neutrally; or even in a basic manner; that is, it takes up 

 the acid color and retains it in the presence of basic 

 after-coloring. If we, therefore, allow a double staining 

 ■with an acid or basic color to act upon a tissue Avhich 

 contains, aside from tiie ordinary nuclei, the above de- 

 scribed total acid nuclei, we obtain a beautiful contrast 

 stain between the two kinds of nuclei, ■ Sucli a method 

 is, for example, the one described by me — the Water- 

 Blue Safannin Method. It shows us the ordinary nuclei 

 blue with the exception of the (strongly acid) small nuclear 

 body, the acid nuclei, however, stained a brilliant red in 

 their totality. 



If one needs only to obtain a special stain of the acid 

 nuclei without double staining, all that is necessary is to 

 decolorize with a concentrated tannin solution the sections 

 over-stained with my polychrome methyl-blue solution or 

 a gentian solution ; they ap})ear in the first instance 

 violet, while the other nuclei are l)lue ; in the second 

 instance they show a red color, while the ordinary nuclei 

 are violet. Altogether it gives the impression as though 

 in these nuclei the reaction and tingibility of the nuclear 

 chromatine had spread over the entire nucleus ; and in con- 

 sideration of the importance of the chromatine in the gen- 

 eration of new nuclei and cells the suspicion arises that the 

 acid nucleus represents a pathological formation. This 

 suspicion is justifiable in so far as one meets them in 



