232 BOTANICAL GAZETTE [SEPTEMBER 
ANALYSIS OF SOLUTIONS BATHING THE TISSUES.—The method | 
of analysis may also be applied to the diffusion from living cells 
(“‘exosmosis’’) of substances normally present in the cells and 
retained by the impermeability of the protoplasm (they may 
accumulate in the cell walls of terrestrial plants in quantities 
sufficient to maintain a condition of equilibrium with the solution 
inside the cell, and may diffuse out when the cells are placed in 
water). Under certain conditions these substances may be made 
to diffuse from the cells in appreciable quantities. The experiments — 
of WACHTER (69) on the exosmosis of sugar from onion bulb scales 
seemed to indicate that this exosmosis was inhibited by various 
salts. In the light of more recent evidence it seems possible that 
this was due to antagonization of traces of toxic salts in the ‘“‘Leit- 
ungs-Wasser”’ which he used. 
Other experiments have dealt with the absorption of salts from a : 
the solution as well as with exosmosis. The results of the experi- oe 
ments of TRUE (63), TRUE and BARTLETT (64, 65, 66), and MERRILL. — 
(34, 35), like those of WAcuTER, were visible only after several - 
hours, and the intervening effects upon permeability could not be 
determined. There was also opportunity for Baa ckmmehs pro- . 
cesses” and other complications to influence the tion of salts 
to a marked extent during this interval, and a probability that Le 
_ some of the external cells would be killed and would give off their A 
contained solut lution. _Ttis quite prot bl : 
that these effects are of importance in exper Ss 
duration as those of the investigators mentioned. The most 
serious objection to using the analysis of the i 
im ents of such | Ca 
of permeability i is that the ‘method does not disting lish - between 
| difasng ov), it it will continue to diffuse i in, while a roubxtance which 
