ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 937 



Bacillariacefe) in tbe small earthy particles remaining attached to 

 the roots. One species, viz. Hantzschia Amjihi/oxys, was only found 

 on the roots of Anemone tetrasepala Royle. 



Conjugatae.* — F. Gay publishes a monograph of the Conjugatfe 

 of the neighbourhood of Montpellier. He describes the mode of 

 gi-owth as twofold : the ordinary growth of the Zygnemeae and Meso- 

 carpefe, and the local growth or " reduplication " of the Desmidiefe. 

 The modes of reproduction described are : partheuogenetic, as seen 

 by Wittrock in the Mesocarpefe, and by the author in Spirogyra 

 loiujatn ; apogamous, also described by Wittrock and De Bary ; and 

 the ordinary sexual mode. 



Floating Eivulariese.f — E. Bornet and C. Flahault review all 

 the alga3 belonging to the Rivulariete described as forming " flos 

 aquae," and conclude that they must all be referred to the genus 

 GIveotrichia, many of them being forms of the species known as G. 

 pisum. Gloeotricliia is reproduced in two ways : by hibernating 

 spores and by hormogonia. Algfe belonging to this group are 

 much more constant in their form than Nostochiueae, such as 

 Tohjpothrix, Scytonema, and Lynghya. 



Sphacelaria. % — V. B. Wittrock finds the rare alga Spliacelaria 

 cirrliosa f3 cegagrophila Ag., on the east coast of Gothland, in the 

 form of globular balls, 1-4 cm. in diameter, not attached, but 

 rolling about free in the water. The balls consist of an immense 

 number of radial threads matted together by their numerous branches, 

 these are collected into two or three concentric layers, each of 

 which appears to be the growth of a year. Two other algae, a 

 diatom and a Cladophora, are epiphytic on the Spliacelaria, and unite 

 with it to make up the floating ball. 



" Sewage-Fungus." § — A. W. Bennett has examined the organism 

 known by this name to sanitary engineers, which appears in white 

 flocculent masses in the effluent water from sewage works. He finds 

 it to be identical with Beggiatoa alba Vauch., or a variety of that 

 species, which is characterized by the remarkable property of 

 eliminating sulphur from the organic or other substances present in 

 the water. This suli)hur appears as minute strongly refringent 

 globules inclosed within the colourless filaments, and generally 

 situated near to a transverse septum or the base of a branch-filament. 



Growth of the Thallus of Coleochaete scutata- 1| — L. Kny states 

 that in the disk-like thallus of this alga attaclied to tlie sides of 

 vessels, cell-growth and cell-division almost invariably take place 

 more actively on the side most exposed to the light. He does not, 



• Gay, F., ' Essai d'une monographc des Conjuguees ' (4 pis.) Montpellier, 

 1884. See Dot Contralbl., xviii. (1884) p. 353. 



t Bull. Soc. Dot. Frana-, xxxi. (1884) pp. 7G-8I. 



X KB. Bot. Gesell. Stockliolm, Feb. 27, 1884. See Bot. Contralbl., xviii. 

 (1884; p. 28:5. 



§ I'rof. Brit. Assoc. Adv. Sci. (Montreal Meeting) Sept. 2, 1884. 



II Ber. DtutHcli. Bot. Gcaell., ii. (1884) pp. 93-G. 



Ser. 2.— V.ji.. IV. 3 Q 



