ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 12 L 3 



follow some of the species-names, and general comparisons are drawn 

 between the diatom floras of Bear Island, Spitzbergen, and Jan May en. 

 A second contribution to tlic flora of Bear Island follows Miss 

 Cleve's paper, the subject being the Vegetable Plankton of the Lakes, 

 by G. Lagerheim. The organisms in question were obtained from Lake 

 Ella and from a pond in the neighbourhood of the Russian harbour. 

 Each locality is treated separately, each species-name being followed by 

 remarks on its geographical distribution. Only six species are recorded 

 from Lake Ella of which one, Hormospora subtilissima is new ; while 

 fifteen species were found in the pond near Russenhafen. The author 

 finds no Peridineee in Bear Island, the plankton of which resembles in 

 this respect that of Lapland, investigated by Prof. Cleve ; but the 

 similarity between the two regions is only negative, for the species 

 recorded from eacb locality are as different as possible. Remarks on 

 the distribution of forms found in Bear Island close this paper. 



Algae from the Caroline Islands.* — W. Schmidlo and Major Rein- 

 bold publish, in two papers, records of fresh-water and marine algse 

 respectively. They are collected principally from the Island of Yap. 

 Schmidle records twenty-four fresh-water species, of which three are 

 new : Plectunema VolJeensii, Pithoplwra variabile, and Cosmarium Lindaui. 

 A new variety and a new form are also described. Critical notes, vary- 

 ing in length, are appended to each record, and two of the new species 

 are figured, as well as the new form and variety. Major Reinbold re- 

 cords twenty-four marine species. 



Fungi. 



Pyrrhosorus, a new Marine Fungus.f — This new genus was found 

 by H. 0. Joel on a decaying alga, Cystoclonium purpurascens. His 

 attention was drawn to it by the bright yellow appearance of the alga. 

 On examination he found that some of the cells were packed with a 

 sorus of orange-coloured, spherical, naked cells, which at a later stage 

 developed zoospores also brightly coloured. A detailed investigation 

 revealed the following stages in the life-history of the fungus: naked 

 solitary cells which succeed the zoospores, and of which one or more 

 may fuse and form a multinucleate Plasmodium large enough to occupy 

 more than one cell of the Cystoclonium, and becoming more amoeba-like 

 in form. At a later stage the plasmodium divides into vegetative cells, 

 and these form the round spore-mother-cells about 8 fx in diameter. 

 By three successive divisions these come to lie in groups of eight, 

 in sori, as already noted, and finally develop into pear-shaped zoospores 

 provided with two lateral cilia. The author places Pyrrhosorus in the 

 PhytomyxineaB near to Tetramyxa. The different stages are well illus- 

 trated by drawings and by microphotographs. 



Sexual and Non-sexual Reproduction in the Zygomycetes. % — 

 Prof. 0. Brefeld points out that in the Zygomycetes the complexity of 

 the sexual and non-sexual modes of reproduction are, as a general rule, 



* Hedwigia, xl. Heft 6 (1901) pp. 343-51 (1 pi.). 



t Bihang k. Svensk. Vet.-Akad. Handl., xxvi. pt. 3, No. 14, 16 pp. and 1 pi. 

 X Jahresber. Schles. Ges. Vaterl. Cult., Dec. 13th, 1900, 14 pp. See Bot. 

 Centralbl., lxxxviii. (1901) p. 289. 



