The vital staining of mitochondria with janus green and 

 diethyl safranin in human blood cells 1 ). 



by 

 E. Y. Cowdry. 



Anatomical Laboratory, Johns Hopkins University 



(With Plate IX.) 



Object. 



The literature concerning 1 mitochondria in the blood cells of man 

 is very scanty. Benda in 1899 (p. 380) described mitochondria in the 

 polynuclear leucocytes of a nasal polypus. A few years later 

 Schridde ('05, p. 695) studied the so-called Altmann's granules in 

 lymphocytes in tissues under pathological conditions, particularly in 

 lupus of the skin, by means of a modified Altmann's method. 

 Beckton ('09, p. 187) also observed Altmann's granules in lymphocytes 

 and Klein ('10, p. 683) recorded them in lymphoblasts and myelo- 

 blasts in addition. It seems probable, from the discussion in the 

 Berliner Hämatologische Gesellschaft of another paper by Klein 

 ('10 a, p. 406), that the Altmann's granules, which he described with 

 Schridde and Beckton, are identical with the mitochondria of Benda. 



A valuable review of the literature relating to mitochondria in 

 the blood cells of lower forms is given by Duesberg ('12, p. 799). 



This neglect of mitochondria on the part of hematologists is the 

 more surprising in view of what we now know of their functional 

 significance. The evidence is pretty strong that they increase and 

 decrease in number with certain changes in the activity of the cell. 

 So that we have a cytoplasmic as well as a nuclear criterion of cell 

 activity. Moreover the belief is becoming widespread that they play 

 the rôle of plastids in the formation of certain products of cell dif- 



l ) Aided by the Carnegie Institution. 



