ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 609 



Algal Flora around Greifswald.* — M. Schultz publishes the second 

 part of the account of the algal flora of the environs of Greifswald which 

 is being worked out by Schiitt and his pupils. The first part was 

 published by Wilczek in 1918. The region concerned lies between 

 13° 2' and 13° 5' E. long, of Greenwich, and between 54° 6' and 54° 9' 

 N. lat., and is especially interesting on account of its purely fresh -water 

 and purely salt-water pools, as well as every conceivable transition 

 between them. The author proves that the whole southern part of the 

 region, the Ryck-Torfmoor, is distinguished by brackish water, as A. von 

 Chamisso had already conjectured. Since the region belongs to the 

 level lower Pommeranian littoral, the watershed has an extraordinarily 

 slight gradient. The differing salinities of the waters determine in a 

 marked degree the habit of the algal flora, which depends less on the 

 diversity of the species than on the frequency of their occurrence. 

 Specially striking is the capacity of the fresh-water algee for accommo- 

 dating themselves to the brackish water. Only a few families were 

 found to occur exclusively in fresh water. Characteristic of the brackish 

 water were species of Enteromorpha, Vaucheria, Cladophora, Rhizoclonium, 

 together with a few species of Spirogyra, Zijgnema and MougeoUa. And 

 in peaty pools with a salinity of 4 p.c. were flourishing some species 

 of the fresh-water genera — Q^dogonium, Ulothrix, Aphanothece and 

 Tohjpothrix^ OsciJlatoria, Spirvlina and Lynghya. As to the Diatoms 

 they flourish for the most part equally well in both fresh and brackish 

 water, and pass easily from one to the other. Characteristic of fresh 

 water are a number of forms, including Volvox, Eadorina, Pandorina, 

 Goniimi, Stigeoclonium, Draparnaldia, Zygnema, MougeoUa, Splrogyra 

 and all the Confervse, also the Characea3. The slight occurrence of 

 Oscillatoria and Lynghya seems due to the absence of organic matter. 

 The seasonal distribution of the forms is described. The systematic 

 enumeration contains thirty-six Schizophyceae, five Flagellata, one 

 hundred and forty-one Diatomacese, seventy-eight Chlorophycese, one of 

 the Florideffi, two Peridiniete, and nine Characeae. 



Algal Flora around Greifswald.f — J. Klemm publishes the third 

 part of the account of the algal flora of Greifswald which is being 

 worked out by Schiitt and his pupils. The region in question lies 

 between 13° 5' and 13° 8' E. long, and 54° 6' and 54° 8' N. lat. 

 Coast-land is included, containing areas of brackish water. The 

 subject is treated in considerable detail. As regards the land flora, the 

 author finds that in January and February no growth takes place. 

 March and April are the season of maximum growth of Flagellates, and 

 the spring maximum of Diatoms and certain Chlorophycea^, notably, 

 Spirogyra, Zygnema, Conferva, Ulothrix. In May begins the time for 

 the greatest number of species to occur. In June to August the 

 following reach their maximum : Desmidiacese, Protococcoide^ and 



* Beitrage zu einer Algenflora der Umgebung von Greifswald. Dissertation. 

 Greifswald: (1914) 77 pp. (1 map). See also Bot. Centralbl., cxxxii. (1916) pp. 

 471-2. 



t Beitrage zu einer Algenflora der Umgegend von Greifswald (siidostlich von 

 Neuenkirchen). Dissertation. Greifswald: (1914) 87 pp. (1 pi.). See also Bot. 

 Centralbl., cxxxii. (1916) pp. 456-7. 



