The vital staining of mitochondria with janus green etc. 283 



Conclusions. 



1. Mitochondria occur, and can be demonstrated by vital staining 

 with janus green (diethylsafraninazodimethylanilin) and diethylsafranin, 

 in the lymphocytes, large lymphocytes (transitional and large mono- 

 nuclear leucocytes), finely granular leucocytes (neutrophiles) and occa- 

 sionally in the coarsely granular leucocytes (eosinophiles) and platelets 

 of normal, adult, human blood (pp. 10 — 13. figs. 2 — 6). 



2. Mitochondria are totally absent in the nonnucleated red blood 

 cells of normal, adult, human blood (pp. 15 and fig. 1). 



3. These two observations are in accord with the current con- 

 ceptions of the physiological significance of mitochondria. They show 

 that mitochondria are, to some extent, indicators of cellular activity; 

 for mitochondria are present in the active stages of cytomorphosis 

 (lymphocytes, large lymphocytes and finely granular leucocytes), and 

 absent in the terminal or later stages (nonnucleated red blood cells). 



4. The term .nongranular leucocytes', although it is of the 

 greatest convenience for descriptive purposes, is in reality a mis- 

 nomer, for the so-called nongranular leucocytes all contain mitochon- 

 dria. In other words, there exists in the leucocytes, in addition to 

 the specific granulations of Ehrlich, a series of general granulations 

 called mitochondria, which are known to be one of the most funda- 

 mental constituents of protoplasm and to be of great importance in 

 cell physiology. 



Description of Figures. 



All the figures were drawn by me from preparations of fresh 

 normal, adult, human blood stained in a solution of 1 : 10,000 janus 

 green in 0,85 °/ sodium chloride solution and observed by direct 

 illumination from an incandescent gas burner. Zeiss apochromatic 

 objective 1,50 mm, numerical aperture 1,30, and compensating ocular 

 8 with a camera lucida were employed. The outlines were traced 

 but, owing to the movement of the cells, the mitochondria had to be 

 sketched in freehand. The cells, as they are represented on the plate, 

 are magnified about 2,600 diameters. 



1. A red blood cell devoid of mitochondria (p. 9): 



