ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 473 



or rather zoospores. He describes and figures the various stages in the 

 formation of the latter and speaks highly of the investigations of 

 P. Bergon published in 1907. The ultimate fate of the bi-flagellate 

 zoospores is at present unknown. Pavillard figures a cell of Goscino- 

 discus invaded by a fungus, perhaps a Synchsetophagus. Another intra- 

 cellular parasite found in pelagic diatoms is the fungus Olpidium. 



Fossil Diatoms.* — A. Lauby gives a resume of our knowledge of 

 the fossil Diatoinaceae at the present time, their geological strata prin- 

 cipally in the Tertiary and partly in the Quaternary epochs, their 

 geographical distribution over the globe, and more particularly their 

 distribution in French strata. He also discusses the constitution of 

 diatomaceous deposits, the structure of diatoms in relation to their em- 

 ployment for industrial purposes : for instance, for absorption of liquids 

 such as nitroglycerin. He considers also the proportion of soluble silica 

 contained in them, and indicates the uses to which they are put- 

 polishing powders, dentifrices, filters, absorbants, insulating material, etc. 



Austrian Diatoms. f — R. Handmann and F. V. Schiedler write 

 papers on the diatoms of the Alrnsee and the Ibrner Moos, in Austria. 

 The Almsee near Griinau is shallow, and in parts overgrown with Ghara 

 and Potamogeton. Seventy-nine species of diatoms have been found 

 among the Ghara. A new genus, Handmannia (H. austriaca Peragallo), 

 is described by F. V. Schiedler, resembling a Gocconeis. Among the 

 Potamogeton were many species of Gocconeis, Gomphonema, and Symbella 

 Ehrenbergii. The two latter also occurred plentifully among the Ghara. 

 In the mud at the bottom were found G. Ehrenbergii and Navicula 

 Gendrei var. n., Pantocsekii M. Per. (intermediate between Navicula 

 Tuscula and N. amphibola Cleve). The diatom flora of the affluent, 

 the Kellerbach, consists of (51 species, and that of the marshy land 122. 

 The total number of the region is 191, of which Navicula forms -43 p.c. 

 A new species, N. ramingensis Handm., is described. From the Ibmer 

 Moos, Schiedler records 65 diatoms, including a new Gocconeis, twice the 

 size of G. placentida. 



Fresh-water Algae in relation to Medium. J — J. Comere publishes 

 a long paper on the action of the medium in relation to the general 

 distribution of fresh-water algae, which is of great importance in 

 the study of the morphology of algae owing to their extraordinary 

 adaptability to varied conditions. It is divided into three parts. 

 1. Classification of aquatic formations ; biologic nomenclature ; florules 

 corresponding to the conditions described. 2. Influences exercised on 

 the algae by the diverse ecologic factors. 3. General biologic distribu- 

 tion ; factors determining dispersal of algae ; statistics of the principal 

 groups found under the various conditions ; periodicity of development. 



* Rev. Gen. Sci. Decembre 1911, 20 pp. (19 figs.). See also Bull. Soc. Bot. 

 France, lix., 1913, pp. 800-1. 



t Mitt. Mikrolog. Ver. Linz, 1913, pp. 4-37. See also Bot. Centralbl., cxxv. 

 (1914) p. 622. 



X Bull. Soc. Bot. Prance, lx. (1913) Mem. 25, 96 pp.. 



