EXTREME ALTERATIONS OF SER Miahia 
WITHOUT INJURY 
(WITH FOUR FIGURES) 
W. J. V. OSTERHOUT 
It has been pointed out in a previous paper" that in the opinion of 
some writers permeability is a relatively fixed property of the cell, 
and that it is altered only as the result of injury; the alteration is 
then irreversible. Others assume? that there are reversible changes 
in permeability which may form a normal part of the activities of 
the cell. In view of the fact that such changes may control metab- 
olism, it seemed important to establish the truth or falsity of this 
assumption by rigorous proof. 
This was successfully accomplished by the use of quantitative 
methods. The previous paper contained a brief statement of some 
of the results obtained; the present paper adds important data and 
describes subsequent experiments in which an extreme range of 
permeability was attained and very rapid changes were investi- 
gate 
The permeability was measured by determining the electrical 
resistance of living tissues of Laminaria saccharina by a method 
which has been previously described.’ 
It has been shown that the electrical resistance of the living 
tissue falls rapidly where it is transferred from sea water to a solu- 
tion of NaCl of the same conductivity, and that within certain 
limits this effect is reversible. Tissue which in sea water had a 
resistance of 1020 ohms‘ was placed in a solution of NaCl 0.52M 
which had the same conductivity as the sea water. In the course » 
of five minutes the resistance fell to 830 ohms. The tissue was 
replaced in sea water; the resistance soon rose to normal and so 
continued during the remainder of the day. 
* Science N.S. 36:350. 1912. 
? Cf. H6per, Physikalische Chemie der Zelle und Gewebe. Kap. 7 und to. 19!!- 
3 Science N.S. 35:112. 1912. 
4 All readings were taken at 18° C. unless otherwise stated. 
Botanical Gazette, vol. 59] in 
