536 Physologie. — Palaeontolgie. 



pothese denkt sich Verf. das Chlorophyll im Blatt eine Fabrik von 

 Elektronen, welche die Photosynthese bewirken. 



Tswett (Warschau). 



Schönland, S., On the absorption of water by the aerial 

 organs of sorae succulents. (Trans, roy. Soc. S. Africa. I. 

 p. 395—401. 1910.) 



The writer concludes that Mesembrianthemum barbatum and 

 Anacampseros filamentosa cannot absorb any appreciable quantity 

 of water through their aerial organs. Crassula cymosa can do so to 

 a smale extent, but the marginal papillae of this species are not 

 waterabsorbing organs. He doubts the view that many other South 

 African succulents can absorb, by means of their aerial organs, 

 water of sufficient quantity to make good loss by transpiration. 



A. D. Cotton. 



Marloth, R., Notes on the absorption of water by aerial 

 organs of plants. (Trans, roy. Soc. S. Africa, I. p. 429—433. 

 1 PI. 1910.) 



The author discusses the conclusions of Schönland noted 

 above. He states that the anatomical structure of the apical hairs 

 on the bases of Mesembrianthemum densum, M. barbatum show 

 them to be well adapted to the absorption of water at all events in 

 the younger State of the leaf. Experiments with the leaves of Cras- 

 sula tomentosa showed that the plant was able to absorb a conside- 

 rable amount of water through its leaves. A. D. Cotton. 



Tswett, M., Eine Hypothese über den Mechanismus der 

 photosynthetischen Energieübertragung. (Zeitschr. ph5 T sik. 

 Chem. LXXVI. p. 413—419. 1911.) 



Einige theoretische Ergebnisse der vorstehend referirten Mo- 

 nographie der Chromophylle. Die nachweislich photos3'nthetiseh 

 aktiven Komponenten der Chromophylle (Chlorophylline a, ß\ y, 

 Phykocyane und Pykoerythrine) sind lauter luminescierende. in 

 der Pflanze wahrscheinlich phosphorescierende Substanzen. Sie 

 können als zweckmässige Transformatoren der an sich wirkungslo- 

 sen polychromatischen Strahlung in intensive monochromatische, 

 von H 2 C0 3 elektiv absorbierten und auf dieselbe unmittelbar wir- 

 kende betrachtet werden. Als Stütze dieser Auffassung können 

 Brown's und Escombe's Versuche angeführt worden, welche eine 

 sonst unerklärliche photosynthetische Induktion entdeckten. 



Autorreferat. 



Berr y, E. W., Systematic Paleontology — Pteridophyta, 

 Cvcadophytae, Gymnospermae, Monocotyledonae , Dicotyledonae. 

 (Maryland Geol. Surv. Lower Cret. p. 214—508. tf. 2—15. pl. 22— 

 97. 1911.) 



The fossil plants from the Potomac Group of the Maryland-Vir- 

 ginia area very largely outnumber all other classes of organic 

 remains in these deposits and constitute the largest and most varied 

 Lower Cretaceous flora from any part of the world that is known. 

 They also represent chronologically a large part of Lower Cretaceous 

 time, the greatest break being that between the Arundel and 

 Patapsco formations, amounting approximately to all of the Aptian 

 stage of Europe. 



