440 WARREN H. LEWIS 



mitochondria contained mostly large vesicles; cells with rods and 

 granules, small vesicles. As the mitochondria changed into 

 vesicles they lost most of the blue color if previously stained with 

 janus black no. 2. At the same time they appeared to become 

 somewhat darker or more opaque than normal, and were then 

 more easily seen, especially when they became spherical. The 

 vesicles in certain foci appeared as dark rings. 



In changing from threads and rods to vesicles the mitochondria 

 often became at first irregularly varicose with swollen places 

 here and there. Two or more swollen places often developed on 

 the longer threads and rods and remained connected for a time 

 by narrow segments; these later expanded, forming oval vesicles 

 which changed to spherical ones. The threads and rods short- 

 ened quite perceptibly as they expanded. The factors which 

 cause the rounding up of the mitochondria can only be surmised. 

 It seems evident that they take up fluid and increase in volume. 

 The potassium permanganate causes, perhaps, an increase in the 

 permeability of the cytoplasm, so that not only the cytoplasm 

 itself, but also the mitochondria take up water, since both 

 swell. If, as is commonly supposed, mitochondria are composed 

 of phospholipins, a simple explanation of their swelUng can be 

 offered, since the affinity for water is increased when phosphohpins 

 are oxidized.^ It seems probable that there is also an increase 

 in the surface tension of the mitochondrial substance which is 

 normally rather low. The transformation of mitochondrial 

 threads and rods into vesicles by the action of potassium per- 

 manganate is not a specific reaction to this substance, as it can 

 be brought about by other reagents and is not infrequent in the 

 later stages of cell degeneration in cultures that have not been 

 disturbed. 



CHANGES IN THE CYTOPLASM AND CENTROSPHERE 



There was very little alteration to be seen in the cytoplasm 

 of the living cell. More or less swelling of the cells occurred, 

 sometimes blebs appeared or the cells rounded up somewhat. 

 There was often more or less liquefaction and Brownian motion 



^ Mathews, A, P. 1915 Physiological chemistry, p. 98. 



