ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 83 



Thallophyta. 



Algae. 

 (By Mrs. E. S. Gp:pp.) 



Swedish Plankton Algge,* — Einar Telling gives an account of 

 the phjtoplankton of the Kiistasjo, a fresh-water lake near Stockholm. 

 He summarizes in a tabular fashion the 75 forms collected, showinsr 

 their relative abundance or rarity in the autumn and winter months, 

 and then discusses the more interesting species, adding some figures 

 and a bibliography. 



Fresh-water Algae. f—G. S. West publishes a further instalment of 

 his algological notes, X-XIII. The first of these consists of observations 

 upon two species of CEdogonium^ with some remarks upon the origin of 

 the dwarf males. The species in question are CE. rivulare A. Br. and 

 CE.fontkola A. Br. Suggestions are made as to the evolution of the 

 sexual differentiation in (Edogonium. In XI, the author describes the 

 resting-spores of Surirella sjnralis Kiitz., which were found to be eight 

 in number. Thick-walled resting-spores, such as those here described, 

 have been seen in very few fresh-water species and only in a few genera 

 of marine plankton diatoms ; but in none of these cases have eight 

 spores been observed within the walls of the original mother-cell. XII. 

 A new genus of Volvocaceae, Scourfieldia, which is remarkable for its 

 backward mode of progression, the reverse of the usual method in 

 Chlamydomonadeae. In XIII, new and interesting British fresh-water 

 algae are described, one, Dicranochsete britannica^ being new to science. 



Life-history of Marine Diatoms. f — J. D. Siddall publishes notes 

 on the life-history of some marine diatoms from Bournemouth collected 

 by surface-netting, especially of a small yellow Goscmodiscus, to which 

 he gives the name O. heliozoides to distinguish it as a species or variety 

 from 0. radiatiis. This diatom is beset with exceedingly delicate pel- 

 lucid pseud opodial filaments, varying in length up to 5 or 6 times the 

 diameter of the frustule. Apparently they are produced by the very 

 youngest examples, and later become stiffened and probably somewhat 

 silicified ; but still they function as tactile organs, being coated to their 

 tips with a layer of living protoplasm. They emerge through canals in 

 the cell-wall. Three modes of reproduction occur : (1) the ordinary 

 method ; (2) liberation of chromoplasts in protoplasm from inside the 

 frustule ; (3) detachment of granular protoplasm from outside. 



Algological Notes. § — 0. Nordstedt continues his notes on algae. 

 In Vlll he discusses the nomenclature of Ectocarpus reptans Crouan, 

 which has been confused by authors. He explains his reasons for giving 



* Svensk. Bot. Tidsskr., vi. (1912) pp. 266-81 (figs.). 

 t Journ. Bot., 1. (1912) pp. 321-31 (figs.). 

 X See this Journal, 1912, pp. 377-81 (2 pis.). 

 § Bot. Not., 1912, pp. 237-9. 



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