408 SUMMAEY OF L'UKRENT RESEARCHES RELATING TO 



wh|ch substance has never before been recorded for any species of 

 ChlorophyceiB. No reproductive organs were found. Resting spores 

 arise by sprouting from the rhizoids and contain a fat oil. Bodies are 

 also present which are difficult to determine, but might be pyrenoids. 

 The author thinks that his plant is identical with Botrydium pyriforme 

 Kiitz., and considers that it constitutes a new genus, Geosiphon, and 

 represents a heterotrophic form in the Siphonea? series. 



In the vesicles of Geosiphon, typical colonies of Nostoc were always 

 present. These in the opinion of the author belong to a new species, 

 N. symbioticum. It always fills up the space of the mature vesicle left 

 empty by the protoplasm, and is present in all vesicles, large or small. 

 It dies off with- the old vesicles, leaving resting-cells which enter the 

 rhizoids and are presumably conducted up to the vesicles by the 

 streaming of the protoplasm. The author considers that this is an 

 interesting case of symbiosis, suggesting an analogy with that of lichens. 

 He points out the presence of chitin in both Geosiphon and lichens, and 

 suggests that this substance is connected with the organic nutrition. 

 As regards systematic position, Geosiplion represents a strongly aberrant 

 form "outside the Siphonete series. From a purely morphological stand- 

 point Geosiphon forms a link between Botrydium and Vaucheria. 



Systematic Position of Halosphsera.* — C. H. Ostenfeld has studied 

 Halosphsera, and sums up his results as follows : — In March, 1914, the 

 author observed, in the tropical Atlantic, a cell of Halosphsera, the 

 contents of which were formed into zoospores of an amoeboid or, better, 

 a metabolic character. They were pale yellowish -green with a trans- 

 parent apex, behind which a carmine eye-spot was found ; no Hagella 

 were seen. The author proposes to place Halosphsera in the Hetero- 

 kontffi (in the neighbourhood of Botrydiop)sis and Botrydium) for the 

 following reasons : — 1. The numerous small yellowish-green chroma- 

 tophores. 2. Oil, not starch, as result of the assimilation. 3. The cell- 

 wall being built up of two layers. 4. The constitution of the cell-wall 

 being of pectines and siliceous matters. 5. The power of the zoospores 

 to alter their shape. Eesearch is still needed as to the character of the 

 flagella of the zoospores. 



Siberian Algae.f — H. Printz publishes the first part of his botanical 

 experiences during the Norwegian Scientific Expedition to Southern 

 Siberia and Uriankailand in the summer of 1914. The author gives 

 in the introduction a short account of the journey in the Sajaner 

 Mountains between Siberia and Mongolia, and describes the orographical, 

 cUmatic, and vegetative conditions. Then follows a list of the algfe- 

 localities, and of the Chlorophyceffi observed, with the exception of the 

 Desmidiaceae. Many new species and varieties are described and 

 figured, as well as two new genera of Chaitophoraceae — Epibolium and 

 Lochmium. 



* Bot. Tidskr., ii. (1915), p. 70. See also Bot. CentralbL, cxxsi. (1916) p. 424. 

 t Kgl. Norsk. Vidensk. Selsk. Skrift., xviii. (Trondjem, 1916) 52 pp. (7 pis.). 

 See also Bot. CentralbL, cxsxi. (1916) pp. 509-10. 



