( 574 ) 
Botany. — “Contributions to the knowledge of the movement of 
water in plants ” By Dr. K. Zijlstra. (Communicated by 
Prof. J. W. Moll). 
(Communicated in the meeting of January 29, 1910). 
For some time I have been occupied in the botanical laboratory 
at Groningen with the problem of the movement of water in plants 
and have carried out experiments of a somewhat diverse nature. 
Various circumstances have prevented me from continuing my ex¬ 
periments in this direction, so that the investigation has not been 
rounded off. I did not intend publishing it, but as I shall presumably 
have for some time no further opportunity of continuing my studies, 
I think I may be justified in publishing the data I have collected; 
possibly they may be of service to other investigators who have chosen 
for their researches the subject of the movement of water in plants. 
The experiments referred to may be arranged under three heads, viz.: 
1 st . The trunk or stem of intact plants cooled to about 0° C. 
2 nd . The ascent of a dye solution in cut branches. 
3 rd . Interference with the movement of water in a tree-trunk by 
means of deep incisions. 
First I propose to discuss the considerations which led to these 
experiments and the results obtained, and then I will give a more 
detailed account of the execution of the experiments. 
1. Trunk or stem of intact plants cooled to about 0° C. 
As is well known, Godlewski (Zur Theorie der Wasserbewegung 
in den Pflanzen. Jahrb. f. Wiss. Bot. Bd. 15) attempts to find the 
cause of the movement of water in the activity of the living cells 
of the medullary rays and of the wood parenchyma; these cells 
would therefore have to act as it were as suction-pressure pumps. 
Godlewski did not, however, adduce any direct experimental evidence 
in support of this theory. His theory is only made plausible with 
the aid of various data obtained by others, and it is urged that the 
theory does not conflict with the facts adduced by other investigators. 
Various botanists (Jansk, Strasburger, Weber, Ursprung) have after¬ 
wards attempted to test the theory experimentally. 
The most obvious method for such a test would be the following: 
to cut out the action of the living cells of medullary rays and wood 
parenchyma, and then to see whether the movement of water had 
become impossible. 
