Physiologie. — Algae. 341 



of the leaf was strongly chlorotic and remained so until treated 

 with iron. 



Ash analyses gave similar results. M. J. Sirks (Wageningen). 



Lacsny, I. L., Ajäszöi halastavak kovamoszatai. [Die 

 Bacillarien der Jäszöer Fischteiche]. (Botan. közl^m. 

 XVI. 1/3. p. 12—20. Textfig. Budapest 1917. Magyarisch.) 



Die Teiche liegen im Tapolcza-Tale im Komitate Abauj 

 Torna. Aber nur zwei haben sich erhalten. Der obere kleinere ist 

 recht seicht, von Wasserblütenpflanzen ganz bedeckt; der untere 

 grössere hat am Boden reiche Myriophyllian-W eget3.i\on, an den 

 Rändern Schilf, Rohrkolben, Scivpiis, Carex. In beiden Teichen fand 

 Verf. 82 Arten, im grossen 36, in kleinen 55; 12 Arten kommen 

 in beiden vor. Von den 82 Arten kommen 50 im Balatoner See, 

 35 in den Penninen, 26 in den Surjäner Meeraugen vor. Das 

 Material revidierte Josef Pentocsek. Neu sind: Navicula salina- 

 rurn Grün. n. var. graciUor, N. Sancti Norherti n. s'p., AchnatJthidium 

 flexellum Br. n. var. ininuta, Grunowia Takdcsi n. sp., Suriraya 

 turgida W.Sm. n. var. punctata, Fragilaria parasitica (W.Sm.) n. var. 

 rhonibica. Matouschek (Wien). 



Lohmann, H., Beiträge zur Charakterisierung des Tier- 

 und Pflanzenlebens in den von der „Deutschland" 

 während ihrer Fahrt nach Buenos Ayres durchfahre- 

 nen Gebieten des Atlantischen Ozeans. I. und II. Teil. 

 (Int. Rev. ges. Hydrobiol. u. Hydrogr. IV. p. 407 — 432. 1912. V. p. 

 185—225, 343-372. Fig.) 



Observations in cool water, north and south: On the 

 whole the cool water was characterised by the great number of 

 Diatoms and of naked Phytoflagellates as well as by the rapid 

 growth, Coming on by leaps, of the microscopical plants in general. 

 Coccolithophoridae and Peridineae appeared besides these predomi- 

 nating plants. In the north the region of cool water stretched unto 

 the Azores, in the south it began with the 25th degree south lati- 

 tude. North of the Azores there was of special interest the appea- 

 rance of the numerous dead Nerophus floating on the surface of 

 the sea which accompanied the ship for nine days. In the south: 

 Beginning on May 30, there appeared floating Macrocystis and with 

 it Oestrelata, penguins and Diatoms of the A.ntarctic Sea. The Mi- 

 croplankton was in the north richer in Diatoms, in the south richer 

 in Phytoflagellates. The cause of this difference is to be looked for 

 first in the different season, and then in the different parts into 

 which the two great circular currents (north equatorial and south- 

 equatorial current) were cut by the ship. 



Observations in the tropics (Nan no- and Micropia nk- 

 ton): In Opposition to the region of cool water the Diatoms and 

 naked Phytoflagellates receded completely in the tropics, so that the 

 Peridineae and Coccolithophorideae became the predominating plant- 

 families. As a new species there appeared Trichodesmium , which is 

 characteristic for this region, yet it occurred in considerable num- 

 bers only in the North equatorial and in the Guineacurrent and 

 several times changed the colour of the water. The whole region 

 of the tropics can, according to our experience, be separated into 

 the region of the north- and south-tropics and into that of the 



