362 BOTANICAL GAZETTE [APRIL 
reaction. This accords with the evidence on the animal side, and stands in 
opposition to WASSILIEFF’s view that asparagin is the immediate material from 
which plant proteins are synthesized, and to the PFEFFER view that proteins 
may be synthesized by the installation of NH; into organic compounds without 
the amino acids as intermediate forms. ZALESKI raises the question whether 
the same enzymes cause both the condensation and hydrolysis. Both protease 
and rennin were found in the ripening seeds, but no tests were run for ereptase. 
The hydrolytic activity diminished as ripening progressed, due either to the 
destruction of the enzyme or to its transformation to an inactive form, for no 
evidence for an anti-enzyme could be found.—WILLIAM CROCKER. 
Potassium in plants.—WeEveERS” has om a rather extensive study 
of the distribution of potassium in plan He used, in the main, 
MacCatium’s method of treating the Lee with Seda cobalt nitrite, 
followed, after thorough washing with water, by ammonium sulphide. 
finds potassium in all plants except Cyanophyceae. The nucleus and chloro- 
plast are always potassium-free, while the vacuole is rich in it, and the cyto- 
plasm contains considerable. The writer believes, contrary to MacCALtuM, 
that these reagents are not capable of showing the localization of the potassium 
in the cell. The apparent localization found by the latter worker was probably 
largely due to precipitation determining the concentration gradients in both the 
reagent and the potassium salt. Essentially all the potassium found in the 
lant cell can be dissolved out of the dead cell with either water or 50 per cent 
alcohol, so the author believes the element exists in the form of inorganic salts - 
and not as a part of the protoplasmic organic constituents. The pollen grains 
of Tulipa and Crocus are potassium-free, and will develop normal tubes in a 
potassium-free medium. In these cases then, among the higher plants, 
potassium is not necessary for growth. The absence of potassium in the 
chloroplasts is offered as fatal to the assumption of various workers that it 
plays an important réle in photosynthesis. The author believes that his 
findings agree with the view that potassium in the growing point is connected 
with protoplasm construction, while in the vacuole it aids in the production of 
osmotic pressure. The facts reported in this work, agreeing in the main with 
those reported by MacCatium, show how little we know about the physiologi- 
cal réle of potassium.—WILLIAM CROCKER. 
Development of Laminaria.—The development of the Laminariaceae 
from spore to adult has been very little studied. YENpDo™ has studied the 
development of three forms, Costaria Turneria, Undaria pinnatifida, and 
Laminaria sp., and the results may be summarized as follows: The sporelings 
™ WEEVERS, Tu., Untersuchungen iiber die Lokalization und Funktion des 
Kalium in der Pflanzen. Recueil des Travaux Bot. Néerl. 8:289—332. figs. 3. 1911. 
%YeNDO, K., The development of Costaria, Undaria, and Laminaria. Ann. 
Botany 25:691-715. pls. 53-55. I19tt. 
