Guilliermond - Atkinson 



— 134 — 



Cytoplasm 



times obtained but usually the cells die without having brought 

 this about. 



The study of the behavior of the rose derivative of Janus green 

 in these cells explains these phenomena since the derivative does 

 not behave like Janus green. Whereas Janus green stains only the 

 leucoplasts and chondriosomes, or the vacuole if it contains oxy- 

 flavanol compounds, the rose derivative shows a greater affinity 

 for the nucleus and cytoplasm, as well as for the vacuole containing 

 oxyflavanol compounds, than it shows for the chondriosomes and 

 leucoplasts which it stains only faintly. Therefore, if one uses a 

 dilute solution of Janus green (0.0005-0.005%) the dye stains only 





Fig. 85. — Vital staining with neutral red, except 03, 

 observed under the microscope. A, PeniciUium glaucum. 1, 

 before staining; 2, small deeply stained precipitates in the 

 vacuole showing Brownian movement; 3, fusion of small 

 precipitates to larger bodies; 4, precipitates appressed to 

 peripheral wall of vacuole, diffuse staining of sap. B, 

 Zygosaccharomyces Chevalieri. 1, small precipitates in 

 vacuole; 2, 3, fusion, bodies now appressed to wall of the 

 vacuole, sap diffusely stained. C, Saccharomyces ellipsoideus; 

 1, 2, as in A, 1-2; 3, cells fixed by formol stained with cresyl 

 blue which causes flocculation of the metachromatin from the 

 colloidal substances in the vacuole as numerous, deeply 

 stained bodies. 



the chondriosome and leucoplasts but it stains them faintly. It is 

 almost immediately reduced to its rose derivative, however, and 

 this diffuses into the cytoplasm, the nucleus, or the vacuole, and its 

 concentration is too weak to produce in them any appreciable 

 coloration. On the contrary, a 0.01% solution of the dye taken up 

 by the chondriosomes and leucoplasts, is reduced to its rose deriva- 

 tive which, being less strongly retained by these elements, diffuses 

 into the cytoplasm and nucleus which it colors a pale rose in cells 

 whose vacuoles are lacking in oxyflavanol compounds. In the case 

 of the vacuole which, on the contrary, contains oxyflavanol com- 

 pounds and has accumulated Janus green, reduction goes on at the 

 same time in the chondriosomes and in the vacuole, and a part of 

 the rose derivative formed in the chondriosomes diffuses into the 

 vacuole. Often indeed, the reduction begins in the vacuole and 

 takes place later in the leucoplasts. 



