The vital staining of mitochondria with janus green etc. 275 



I have employed the nomenclature of blood cells advanced by 

 Weidenreich ('10, p. 320) and adopted by Minot ('12, p. 515). The 

 observations which I venture to record on the occurrence of mito- 

 chondria in human blood cells as demonstrated by staining- with janus 

 green and diethylsafranin are these: 



1. Red blood cells (fig - . 1). 



Sjmonyms: erythrocytes and blood plastids (Minot, '12, p. 503) 



No formed elements may be seen in the fresh, unstained con- 

 dition. 



With janus green, in the concentration employed, the red blood 

 cells remain uncolored. There is no hemolysis and but little crenation. 

 There are no traces of mitochondria. Hypotonic and hypertonic salt 

 solutions were used, with the hope of in some way facilitating the 

 diffusion of the stain into the cell, but still no traces of mitochondria 

 could be seen. 



Diethylsafranin penetrates the cell readily and colors it light 

 pink, but does not stain any mitochondria. 



The study of fixed and stained smears was equally negative. 



2. Platelets (fig. 2, a, b and c). 

 Synonyms : thrombocytes. 



Mitochondria cannot be recognised in unstained platelets. The 

 outlines of the platelets are irregular. They may be homogeneous, or 

 else studded with granules, which may or may not be highly refrac- 

 tile. Sometimes the granules are uniform in shape, at others dimorphic. 



The staining reactions with janus green and diethylsafranin are 

 far from uniform. Occasionally they remain uncolored (fig. 2 a), or a 

 variable amount of internal differentiation may be made out which 

 stains faintly with janus green (fig. 2 b). In rare cases they may be 

 seen to contain bodies with discrete outlines, which vary from gra- 

 nules to rods and which stain brightly with janus green (fig. 2 c). 

 These are mitochondria. They are the highly retractile granules of 

 uniform shape seen in the living, unstained condition. 



In janus green preparations a close association was noted between 



the platelets and granular as well as nongranular leucocytes. Masses 



of cytoplasm were seen to separate from the lymphocytes. After 



18* 



