( 395 ) 
ON THE ABSORPTION OF WATER BY THE AERIAL ORGANS 
OF SOME SUCCULENTS. 
By S. Schonland, Ph.D., F.R.S.S.Af. 
(Read June 16, 1909.) 
Ever since the absorption of water by plants has been the subject of 
experimental inquiry, it has been known that water in liquid form can 
be absorbed by the leafy shoots of many plants, and that even the 
loss by transpiration of other parts of the same plant, which are not 
wetted, can be made good in this manner.''' However, the shape and 
arrangement of leaves on the axis is frequently such as to prevent or 
hinder the formation of dew upon them.f Rain is usually easily drained 
off, and can, as a rule, not readily lodge on them. The absorption of 
liquid water by aerial parts of plants under artificial conditions is, there- 
fore, in the majority of plants, only of academical interest. On the other 
hand there are cases, e.g., the epiphytic BromeliacecB, in which the plants 
are either without roots or provided with an imperfect root-system, and in 
which, therefore, absorption of water by aerial parts becomes a necessity. 
To a limited extent the utilisation of rain-water and dew may also occur 
in other plants, e.g., in cases where the leaf-sheaths collect a considerable 
amount of water. There remain a number of other cases in which water 
is supposed to be absorbed by means of special hairs or glands or by 
means of saline excretions of the leaves. Marloth | has shown pretty 
conclusively that the saline excretions cannot serve to conduct water from 
rain or dew to the organs which secrete them. In his recently published 
* SeeL.Kny, "Uber die Anpassung von Pflanzen gemassigter Klimate an die Aufnahme 
tropfbarfliissigen Wassers durch oberirdische Organe," Ber. d. d, bot. Gesellschaft, iv. 
(1886), p. xxxvi (where the literature up to that time is pretty fully quoted), and " Ueber 
die Aufnahme tropfbar-fliissigen Wassers durch winterlich-entlaubte Zweige von Holzge- 
wachsen," Ibid. xiii. (1895), p. 361. 
t Stahl, " Annales Jard. Buitenzorg," ii. (1893), p. 98, as quoted by Jost, "Lectures 
on Plant-Physiology," Engl. Ed. (1907), p. 32. 
\ E. Marloth, " Zur Bedentung der Salz abscheidenden Driisen der Tamariscineen," 
Ber. d. d. bot. Gesellschaft, v. (1887), p. 319. 
