374 MARGARET R. LEWIS AND WARREN H. LEWIS 



number of small granular rings of uniform size. Hydrogen per- 

 oxide, potassium permanganate and chlorotone, each produce a 

 similar result. 



Reaction to alkalies 



Alkalies, ammonia gas and sodium hydroxide, on the other 

 hand, cause the mitochondria to swell without any sign of vari- 

 cosity. The nucleus also becomes larger and more transparent 

 (fig. 19 b). 



If the ammonia vapor is followed by vapor from acetic acid 

 the acid will cause the mitochondria and also the nucleus to 

 return to the normal condition. We have not succeeded in 

 stopping the action of the acid at this point, however, and the 

 mitochondria become degenerate rings (fig. 19 c). 



Reaction to xylol, chloroform, ether 



Xylol, chloroform, and ether simply remove the mitochondrial 

 material, or possibly dissolve the mitochondria and leave shadow 

 forms or slight traces of degenerate mitochondria. 



Reaction to hyper and hypotonic solutions 



Changes in osmotic pressure affect the mitochondria often 

 before any change is seen in the cytoplasm. Hypertonic solu- 

 tions shrink the mitochondria while hypotonic solutions cause 

 them to become swollen. The effect of a hypertonic solution 

 can be removed by a decrease in the osmotic pressure of the 

 solution, and, vice versa, that of a hypotonic by an increase in 

 the osmotic pressure (fig. 19 d). 



Reaction to heat 



Heat gives interesting results. With an increase in the tem- 

 perature of the warm stage on which the preparation is studied 

 from 40 to 48°C., the mitochondria become round granules within 

 fifteen or twenty irdnutes, regardless of their previous shape 

 (fig. 20). The size of these round granules is determined by 



