722 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which he has observed in this Diatom. He believes that he has also 

 recognised sporolation in a specimen of Ghcetoceras Weissflociii Schiitt 

 or 0. teres Cleve ; but although he could detect a slow movement it was 

 not distinct, and he could not be sure of the number and form of the 

 flagella. Finally he points out that, though Rabenhorst discovered so 

 early as 1K5: J > the phenomenon of reproduction by zoospores, the con- 

 firmation of it has been delayed up to the present day. 



Arctic and North Atlantic Marine Alga?.* — F. Borgesen and 

 H. Jonsson have drawn up a series of tables illustrating the distribution 

 of the marine algae of the Arctic Sea and of the northernmost part 

 of the Atlantic, in order to compare with it the flora of the Faeroes 

 and Iceland. In this list are included species from the coasts of 

 Europe which occur in the N. Atlantic to the north of a line drawn 

 from Lindesnaes in Norway to the boundary between England and 

 Scotland, as well as species from the shores of New England mentioned 

 by Farlow and by Collins. The tables compare the occurrence of species 

 in seventeen different seas and countries in the area treated, and the 

 total reaches 407 Rhodophycere and Phaeophyceaa, 4- 24, which belong 

 strictly to America. Then follow various analyses of this general table, 

 under the headings of Arctic group, Sub-Arctic group, Boreal-Arctic 

 group, Cold Boreal group, and Warm Boreal group. The Chlorophyceae 

 and Cyanophyceae are given in a supplement, as their distribution is 

 insufficiently known. 



Marine Flora of the N. Atlantic, N. Pacific, and Polar Sea.j — 

 H. G. Simmons publishes some most valuable facts on the relation of 

 the marine flora of the above-mentioned seas. It is now more than 

 twenty years since Kjellman's great work on Arctic algae was published, 

 and the work of the present author brings the list of Arctic species up 

 to date. He deals only with Floridese and Phaeophycese, as the 

 synonymy of the other groups is too uncertain to make any comparison 

 profitable. Out of the Kjellman total of 196 species, Simmons cancels 

 31 as being for one reason or another wrongly included. His own 

 Tesults are presented in the form of tables, which are explained in a 

 most exhaustive and interesting text. In the list of Arctic algse he 

 includes all species found along the coast from the Kola Peninsula to 

 Behring Strait, along the northern coast of America, in the Arctic- 

 American Archipelago, on the coasts of Greenland, Jan Mayen, 

 Spitzbergen, Beeren Island and Novaja Semlja. Remarks are made 

 and valuable conclusions arrived at with regard to the present distribu- 

 tion of Arctic species outside the Polar circle, and on the influence of 

 the Ice Age on the flora of the seas in question. The distribution of 

 certain genera, including Laminar ia, Alaria, Lessonia, etc., is studied 

 in connection with the latter subject, and their migration is explained 

 by geological facts. 



Ceramiaceae of New Zealand.} — R. M. Laing has written an 

 account of the Ceramiaceae of New Zealand. The generic descriptions 



* Botany of the Faeroes, Appendix, xxviii. pp. 

 t Beih. Hot. Centralbl., xix. (1905) pp 149-94. 

 \ Trans. New Zealand Inst, xxxvii. (1904) pp. 384-408 (8 pis.). 



