73 



one just referred to? What is the function of these granules in the 

 cell-body, does their presence depend on a special composition of 

 the cnlture-meditnn ? Do the various en/>ymic actions result from 

 their presence? And as to their morphology: is there any connection 

 between these granules and the development of reserve-materials 

 such as fat and glycogen? and is there any reason for identifying 

 them with mitochondria, as some researchers have done? 



I have not carried out an extended cytological investigation. 

 Still, I found that with Torula monosa '), the yeast-cell with which 

 most of the experiments described lower down have been performed, 

 the result of mitochondria-staining after Benda is positive for the 

 volutin-granules — another proof tliat all granules classed as "mito- 

 chondria" upon the basis of these colour-reactions alone, do not 

 necessarily agree in composition ; for these nucleinic-acid-containing 

 granules e. g. stain in the same way as the mitochondria in the 

 liver-cells, which very probably are compounds of phosphatids. 

 When stained with methylene-blue and subsequently differentiated 

 with 1 perc. sulphuric acid the volutin-granules do not r\ all appear 

 to be metachromatic, as was also found by Meyer. The greater 

 cells often show a diffusely coloured vacuole, which is stained 

 violet-red, i. e. metachromatically ; the granules often stain deep- 

 blue as well in forinol as in alcohol-fixation. 



Nor is the methylene-blue-preparation used immaterial to the 

 degree of metachromasia. With methylene-blue "(i-patent" for 

 example a higher metachromasia was found than with Grübler's 

 methylene-blue for bacteria, the latter being probably purer. With 

 toluidin-blue on the contrary nearly all granules are stained meta- 

 chromatically. It is certain, therefore, that metachromasia cannot be 

 taken as a criterion. This, as I said on page 70, also induced me to 

 prefer the term "volutin-granules". Besides with these anilin-dyes 

 the granules can also be demonstrated with carbolic fuchsin; again 

 also by Unna's staining-method (a mixture of two basic dyes : pyronin 

 and methyl-green, of which only the former is taken up by the 

 volutin-granules.) 



With Heidenhain's ferric-hematoxylin the volutin-granules are not 

 or hardly stained when the nucleus of the yeast-cell becomes clearly 

 visible, in some cases we succeeded in identifying in the living cell, 

 with dilute neutral-red, occasionally also with methylene-blue, granules 

 disposed similarly to the volutin. This, however does not occur with 



1) For further information regarding Torula monosa we refer to Kluyver 

 Biochemical Sugar-determinations, (Thesis. Delft 1914, p. 16.) 



