Physiologie. 243 



Czartkowski, A. , Wplyw floroglucyny na powstawanie 

 antocyanu u Tradescantiu viridis,. [EinflussdesPhloroglu- 

 cins auf die Entstehung des Anthokyans bei Tradescan- 

 tia viridis. (Sitzungsber. Warschauer Ges. Wiss. I. p. 23—30. War- 

 schau 1911. Polnisch.) 



Verf. kultivierte Stengel der genannten Art in Lösungen von 

 verschiedenen Zuckern, Glyzerin, mehrwertigen Phenolen und 

 Phloridzin. Dabei zeigte sich folgendes: 



a. Die glucosidartige Natur des Anthokyans wird dadurch be- 

 stätigt, dass der Farbstoff sich um so schneller und reichhaltiger 

 bildete, je grösser die Konzentration der Zuckerlösung ist (Ver- 

 suche mit 0,01%— 3°/ iger Lösung). Besonders Dextrose und Saccha- 

 rose begünstigen die Bildung des Farbstoffes. 



b. Glyzerin sowie von den mehrwertigen Phenolen nur das 

 Phloroglucin und ferner das Phloridzin können zur Bildung des 

 Anthokyans verwendet werden; es entsteht schneller in Lösungen, 

 welche gleichzeitig Dextrose (2°/ ) und Phloroglucin (0,05%) enthal- 

 ten als in den reinen Lösungen. Matouschek (Wien). 



Livingston.B. E., A radioatmometer for comparing light in- 

 tensives. (Plant World. XIV. p. 96—99. Apr. 1911.) 



The common form of porous atmometer with the surface, either 

 coated with lampblack, or made of dark clay, so that it absorbs a 

 considerable amount of radiant energy falling upon it. The instru- 

 ment then becomes a physical apparatus embodying some of the 

 properties of plant foliage, since it is affected much in the same 

 manner as leaves by the evaporating power of the air and intensity 

 of radiation. Moore. 



Schreiner, O. and M. X. Sullivan. Concurrentoxidation 

 and reduction by roots. (Bot. Gaz. LI. p. 273—285. Apr. 1911.) 



A brief review of the literature on oxidation and reduction in 

 plants and animals is followed by an account of the method used 

 in investigating these processes in roots. Sodium selenite was found 

 to be the best reagent for showing reduction, and this indicator 

 demonstrated that the reducing power of roots increased from the 

 time of germination to the sixth or eighth day, when it decreased. 

 Oxidation was determined by placing seedlings in aloin Solution and 

 measuring the red oxidation product coliometrically. The oxidative 

 power was found to be less in young seedlings and increase with 

 age. Nitrates and phosphates increased the oxidizing power while 

 potassium salts, especially potassium iodide, decreased it. It is be- 

 lieved that oxidation and reduction may take place in the same 

 roots in the same Solution. The similarity between the oxidizing 

 action of roots and some catalyzers is remarked upon, — although 

 this similarity is one probably of analogy only. Oxidation is thought 

 to be closely connected with the metabolic activities of the roots, 

 for whatever decreases the growth of the plant and whatever in- 

 creases oxidation, reduction in roots seems to be mostly intracel- 

 lular, while oxidation is manifestly strongly extracellular. Moore. 



Sigmund, W., Ueber ein äskulinspaltendes Enzym und über 

 ein fettspaltendes Enzym in Aesculus Hypocastamun L. 



