The vital staining of mitochondria with janus green etc. 279 



The amount of mitochondria is uniform. They could not be 

 counted. 



The mitochondria were observed, stained with janus green, 

 during- amoeboid movement and phagocytosis of minute foreign par- 

 ticles. In flg. 5 b a pseudopod is represented which is free of mito- 

 chondria at the tip. 



These observations were checked by the study of fixed and 

 stained smears. 



6. Coarsely granular leucocytes (fig. 6 a and b). 



Synonyms: oxyphile, acidophile and eosinophile leucocytes. 



These cells present technical difficulties not encountered in the 

 study of the cells above mentioned. 



In the fresh, unstained state everything is obscured by an abun- 

 dance of coarse, spherical, tightly packed granules. Even the nucleus 

 can only be seen with difficulty. When the cell adheres to either 

 the slide or the cover glass, loses its spherical shape and becomes 

 slightly flattened, the nucleus may be more clearly observed, and, in 

 the majority of cases, in the cytoplasm near it a few small bodies, 

 which may be easily distinguished morphologically from the much 

 larger, coarse, specific granulations. 



The permeability of these cells to janus green is even less than 

 that of the finely granular leucocytes. That is to say it is less than 

 in any of the other blood cells which I have studied. Even when 

 the stain does penetrate, the coarse granules are generally so crow- 

 ded together that the smaller bodies cannot be seen. When the cell 

 becomes flattened, and as a result certain parts of the cytoplasm, 

 particularly in the neighborhood of the nucleus, are less obscured by 

 the coarse granules, some fine granules and rod-like structures may 

 sometimes be seen stained a light bluish green color with the janus 

 green. These are undoubtedly the small bodies observed in the 

 unstained cells, although the transition from the unstained to the 

 stained condition could not be followed under the microscope because 

 of the coarse granules which obscured the view. They may be iden- 

 tified as mitochondria from their shape and staining reactions with 

 janus green. 



