ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 



evolutionary processes affecting multinucleate organs in the Phyco- 

 mycetes and possible algal relatives. 



(Edogonium.* — F. E. Fritsch continues his algological notes, the 

 latest being a description of the structure of a young (Edogomum which 

 he has had under observation for two years. The lowest (attaching-) 

 cell could scarcely be called hemispherical. In a large proportion of 

 young plants the lower surface of the basal cell was more or less com- 

 pletely enveloped by a hyaline substance, of a mucilaginous nature ; 

 and this served to attach the filaments to the substratum. The apical 

 cell was provided with a longer or shorter cap of cell-wall substance 

 with square corners, so that the apex of the filament had a rectangular 

 appearance. It fitted tightly over the filament, which was V-shaped at 

 the apex. This abnormal cap is attributed by the author to the growth 

 of the plants under unfavourable conditions. The theories of Will© 

 and Hirn regarding the mode of origin, etc., of the cap of CEdogonium, 

 are discussed, the author agreeing with the views held by "Wille. The 

 cell-contents of Fritsch's plants point also to abnormality of condition. 



Jlgagropila Sauteri.f — Wesenberg-Lund has studied the growth 

 of this alga in the lake of Soro in Denmark, where it is very common. 

 Every spring the large spherical bodies are seen floating on the surface 

 of the water. The bottom of the lake at a depth of about 4 metres 

 is covered with a dense layer of small individuals, 10-20 mm. long, 

 which forms coherent strata on stones and other bodies. In shallower 

 water (1-1*5 m.) this layer does not occur, but spherical bodies are 

 found lying loosely on the bottom ; and these bodies rise in spring 

 to the surface. The rising is caused by the assimilation, the bubbles of 

 air not being able to escape from the central parts of the densely 

 aggregated filaments of the sphere. 



Northern Plankton.^ — N. Wille undertakes the working out of 

 those species of Schizophyceas which form part of the plankton in 

 latitudes above 50° N. lat. A large work on the plankton of these 

 regions is in course of publication, divided into twenty-one parts, each 

 of which will appear as it is ready. Each species will be fully described, 

 with a figure of the habit and possibly of the structure as well. The 

 part dealing with the Schizophyceae contains also keys to the genera 

 and species, with lists of synonymy and interesting remarks on dis- 

 tribution. The systematic treatment is preceded by an introduction 

 dealing with the structure and life-history of the group. The author 

 remarks that the number of species diminishes from the equator north- 

 wards and southwards, until in the polar seas not one indigenous species 

 would probably be found. 



Phyto-plankton of Asia Minor.§ — A. Forti has examined thephyto- 

 plankton of three lakes in Anatolia, and publishes his results. The first 

 lake is Abullonia-Gol, which is so shallow as to allow a boatman to 



* Ann. Bot., xviii. H904) pp. 648-53 (1 fig. in text). 



+ Acad. Eoy. Sci. Danernark, Bull.,1903, i>]» 167-201 (J map). 



t Nordisches Plankton, Kiel, pt. xx. (1904) 'I'd pp. 



§ Nuov. Notar., xvi. (1905) pp. 1-14. 



