Equilibrium in the Intake of Dyes by Discs of Plant Tissue. 513 
Experimental Results. 
Series 1. Experiments with living tissue. 
Discs of living tissue, prepared as described in the preceding section, 
were immersed in solutions of the following water-soluble dyes : neutral 
red, methylene blue, methyl violet, aniline blue, eosin, and Congo red. 
Fig. i. Course of absorption of neutral red, by living carrot tissue, from solutions of 
various concentratipn. 
The concentration of dye in the external solution was estimated at 
intervals, and the tissue was weighed. 
The results were similar in the case of all the basic dyes employed 
except aniline blue ; the latter dye was not absorbed in appreciable quantity 
from the more concentrated solutions, and the amount absorbed from the 
more dilute solutions was small in comparison with the other basic dyes. 
The results obtained with the acid dye, eosin, resembled those obtained 
with aniline blue, while Congo red, the only other acid dye used, was not 
