478 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Marine Algse from North-East Greenland.*— L. K. Rosenvinge 

 writes on the marine algae collected by the Danish Expedition on the 

 north-east coast of Greenland. He records sixty species, besides two 

 undetermined : five species are new to Greenland and three new to 

 science. A well developed sublittoral vegetation seems to exist at several 

 places in the explored area. Thus, Fucus inflatus forms a vegetation 

 at a few metres depth under low-water mark, the Laminariacese form 

 true associations at a somewhat greater depth, and the Florideae are pre- 

 dominant at other places mostly in still greater depths. One of the 

 most abundant species is Desmarestia viridis. Of the encrusting algae, 

 Lithothamnion laeve is the most common, and fairly frequent are also 

 L. glaciale, L. fo&cundum, Lithoderma fatiscens, Cruoria arctica, and Rho- 

 dermis elegans. Finally the author discusses the flora of Greenland, and 

 compares the different areas. 



Sulphur-flora of Lemberg.-f— W. Szafer records ten species of Schizo- 

 phyceae from some of the sulphur springs in the neighbourhood of 

 Lemberg. The genera represented are Aphanothece and Oscillatoria, 

 and of the species enumerated six are new. 



Gloeothece rupestris. f— J. Brunnthaler has made a study of the 

 effect of external factors on Gheothece rupestris, and publishes his results. 

 His cultures were made with organic and inorganic compounds respect- 

 ively, both in darkness and light. The author finds that the two varie- 

 ties of G. rupestris are brought about by external influences, the var. 

 eavemarum Hansg. being produced by a weak light and var. tepidariorum 

 by a rise in temperature. G. rupestris grows as well on inorganic as on 

 organic nutrition, and retains the power of becoming green under either 

 condition. Light is on the whole more favourable to cultures in inor- 

 organic solution than to those in organic and in nitrate- or phosphate- 

 containing solutions. In most of the cultures light had no influence on 

 the size of the cells. Warmth causes a diminution of the families and 

 an enlargement of the cells ; at the same time the cell-contents become 

 darker. A firm substratum encourages growth. 



Ceratium hirundinella.§ — E. Werner writes on the structure of the 

 frustule of G. hirundinella, describing the plates and their junction. 

 Her material consisted of a form of the species collected in the Sea of 

 Tiberias by Magnus, in which one of the horns was suppressed. The 

 plates composing the frustule do not overlap at all, but merely lie in 

 close contact, probably attached by means of a cement. In a weak solu- 

 tion of potassium hydrate they drop apart. Details and figures are given 

 of the general structure, number and form of the plates, etc. 



Closterium.|| — B. F. Lutman writes on the cell-structure of Closte- 

 rium Ehrenbergii and C. moniliferum. After an historical account of 

 previous work on the subject he describes his methods, and then deals 

 with the chromatophore, the pyrenoids, and the nucleus in detail. He 



* Meddel. om Gr^nland, xliii. (1910) pp. 93-133 (figs, in text), 

 t Bull. Internat. Acad. Sci. Cracovie, 1910, pp. 161-7 (1 pi.). 

 \ SB. Akad. Wiss. Wien, cxviii. (1909) pp. 501-73 (3 pis.). See also Bot. Zeit. 

 lxviii. (1910) pp. 110-11. 



§ Ber. Deutsch. Bot. Gesell., xxviii. (1910) pp. 103-7. 

 || Bot. Gaz., xlix. (1910) pp. 241-55 (2 pis.). 



