﻿144 BOTANICAL GAZETTE [February 



compounds in very weak solution act as a stimulant upon radish, barley, 

 wheat, and pea. This action was manifested in culture solutions containing 

 manganous phosphate in a concentration of 0.002 per cent. 



In the next two papers ^^ experiments with sodium fluorid and sodium 

 silico-fluorid are reported. Both of these substances show a stimulation 

 effect in very great dilution, but the latter is a much more violent poison 



than the former. 



In the fourth paper '^ oxidizing enzymes of plants are considered. 

 Besides the guaiac reaction for these enzymes and that with guaiacol and 

 hydrogen peroxid, the author wg-S able to obtain from many vegetable tissues 

 the reaction of Storch with paraphenylendiamin and hydrogen peroxid. He 

 also found a new reaction for oxidizing enzymes, namely, the production of 

 a deep violet color on addition of tetramethylparaphenylendiamin and hydro- 

 gen peroxid, a reaction which was obtained from various plant tissues. 

 Sodium fluorid and silico-fluorid interfere with the color reactions of these 

 tests, as does also tannin, but not sugars. By addition of two volumes 

 of absolute alcohol to one volume of plant juice, oxidase is precipitated, 

 while most of the other oxidizing enzymes are left dissolved. 



In the fifth paper,'^ the various forms of calcium in plants are treated. 

 In potato and buckwheat only a small amount of lime compounds soluble m 

 water are present, while in barley and clover they are more abundant. It 

 appears that the amount of lime increases with the increase of chlorophyll. 



Burton E. Livingston. 



J 



of the stelar 



system of the higher vascular plants.^® His studies relate to the histogenesis 

 and comparative anatomy of the tissues in the flowering plants, and the work 

 is divided into two corresponding parts. 



In the first part the author describes his investigations on the structure 

 of the stem-apex and root-apex in a number of angiosperms, and comes to 

 the conclusion that the meristematic layers of Hanstein, the dermatogen, the 

 periblem, and the plerome do not correspond at all accurately to the division 

 of the tissues of the vascular plants into epidermis, cortex, and central 

 cylinder, as proposed by Van Tieghem and others. He further finds that 

 there is too much inconstancy in the cell wall reticulum of the growing point, 

 especially in the case of the stem, for it to be regarded as of very great value 

 as a clue to the morphology of the tissues. The author uses exceptionally 



's Aso, K., The action of sodium fluorid upon plant life. Ibid. 5 : 187-195- P^^' 



18-ig, 1902. 



, On the action of sodium silico-fluorid upon plants. Ibid. 5 : 197-19^ 



1902. 



17 



x8 



, On oxidizing enzymes in the vegetable body. Ibid. 5 : 207-235. 1902 



, On the different forms of lime in plants. Ibid, 5 : 239-242. 1902. 



SCHOUTE, J. C, Die Stelar-Theorie. Proefschrift, Groningen, December 1902 



