ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 611 



present in the lake, at its present level, is most favourable to the develop- 

 ment of Chlamydomonas sp. The diatoms present in the lake multiply- 

 best in water much less dense than the dense water at Saltair. At least 

 four species of algtfi are to be found in the part of the lake investigated. 



Algae of TrauRstein and the Chiemgau.'-^ — E. Kaiser publishes the 

 third part of his Algal Flora of Traunsteiu and the Chiemgau, which 

 contains 129 records of species and varieties. Some of these are new to 

 Bavaria. The groups treated are Scbizophycefe, Zygophjcea^, Conjugatse, 

 and ChlorophyceEe. A list of the more important species recorded is 

 given in the " Botanisches Centralblatt." 



Chlorophycese of Central Europe.! — W. Heering publishes a part of 

 the " Siisswasser Flora Deutschlands, Oesterreichs und der Schweiz," in 

 which he deals with Ulotrichales, Microsporales, and CEdogoniales. A 

 key is given first to all the filamentous green algee, including also 

 Siphonales and Siphonocladiales. The treatment of the groups corre- 

 sponds with that followed in the other parts of the work already published. 



Danish Aerophilous Alg8e.| — J. B. Petersen publishes the results of 

 his studies on the Danish aerophilous algae, and describes his experiments 

 to grow them in culture. He treats of their power to resist desiccation, 

 and confirms the results of Schroeder (1886) and F. Gay (1891). The 

 diatoms are specially discussed, and new species described. The mode of 

 life and methods of culture of certain Chlorophycete are described in 

 detail. 



Position of Chromatophores in Red Algae. § — G. Senn discusses the 

 position of the chromatophores in the palisade cells of Peyssonelia 

 Squamaria and Platoma cydocolpa. In diffused light of medium inten- 

 sity they are arranged in antistrophe on the portions of the membrane 

 turned towards the source of hgbt. By illuminating the lower surface 

 of the Peyssonelia thallus, the chromatophores were forced to collect in 

 the opposite ends of the cells, which, though anatomically on the under- 

 side of the thallus, were the most brilliantly illuminated. By prolonged 

 darkening of the cells of Platoma, apostrophe of the chromatophore was 

 produced ; by intensive illumination, parastrophe. The difference 

 between the arrangement of the chromatophores in the palisade cells of 

 marine algre (antistrophe) and of foliage leaves (epistrophe) in optimal- 

 diffuse light is to be explained by the difference of the optical conditions. 

 If these conditions are equalized by the injection of water into the air- 

 containing intercellular spaces which in foliage leaves cause the reflection 

 of the light-rays which penetrate into the palisade cells, it is found that 



* Kryptog. ForschuDgen, Beil. No. 14, iii. Mitt. Bayer. Bot. GeselL, 1916, 

 pp. 30-8. See also Bot. Centralbl., cxxxiv. (1917) p. 25. 



t Siisswasser-Flora Deutschlands, Oesterreichs und der Schweiz, Heft 6 (1914) 

 250 pp. (385 figs.). See also Bot. Centralbl., cxxxiv. (1917) p. 54. 



X K. Dansk. Vidensk. Selsk. Skrift., xii. (1916) pp. 271-379 (4 pis.). See also 

 Nuova Notarisia, xxviii. (1917) pp. 252-4. 



§ Actes Soc. Helvet. Sci. Nat. Geneve (1915) pt. 2, p. 203. See also Bot. Cen- 

 tralbl., cxxxii. (1916) p. 505. 



