ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 389 



Oscillatoria rubescens.* — H. Bachman describes a water-bloom of 

 Oscillatoria rubescens in tbe Rotseo, in the neighbourhood of Lucerne. 

 It occurred in 11)09-10, reaching such intensity in May 1910 that the 

 lake was of a deep copper-red colour. The principal mass of the alga 

 was in the topmost 3 m., and at the banks it was caked into great 

 masses. Towards the middle of June the quantity had begun to decrease, 

 and continued to do so. A rising temperature did not drive the alga 

 into lower layers of water, as had beeo the case in the Ziirchersee and the 

 Baldeggersee, though it was also found plentifully in the water some 

 distance down. The vast quantity of Oscillatoria caused a diminution of 

 the other plankton-organisms, and at the same time a large development 

 of Rotatoria. The water was found to contain an enormous amount of 

 sulphuretted hydrogen, possibly from the decay of the Oscillatoria. 



Polymorphism and Life-history in the DesmidiacesB.f — G. I. Play- 

 fair writes an interesting account of the real conditions of life and 

 development among the Desniidiaceas, the result of fifteen years con- 

 tinued observations of the same species from the same localities, at 

 different times and under a varietv of circumstances. He finds that in 

 Desrnidiaceas, as in other groups of the lower algte, something like 90p.c. 

 of the "species" are polymorphic forms of the other ten ; and it is only 

 by careful tracing out of their life-histories that the specific connexions 

 of their innumerable variations can be established. He refutes the 

 criticisms of West on some of his previous observations. The poly- 

 morphism of Docidium trabecula is dealt with, and notes on and descrip- 

 tions of various forms are given. 



Spirogyra from the neighbourhood of Besancon4 — J. Virieux gives 

 a list of about fifteen species of Spirogyra gathered by him in the neigh- 

 bourhood of Besanyon. Among them is S. Spreeana Petit, which has as 

 yet only been recorded from three localities : Bokhorst (in Holland), 

 Bondy (near Paris), and Islava (in Roumania;. The author will publish 

 later a catalogue of the algaa of the Doubs. 



Codiace3e.§ — A. and E. S. Gepp publish an account of the Codiacese 

 of the ' Siboga ' Expedition, including a monograph of Flabellariese and 

 Udotese. The paper is founded on the collection of Codiaceae made 

 by Weber van Bosse in the East Indian Archipelago in 181)9 and 

 1900, and supplemented by other collections in the British Museum and 

 elsewhere. Thirteen of the genera of Codiacea3 are monographed in 

 detail, and of these three are new, while another, Tydemania found by 

 Weber had heretofore been only briefly described by her. The genus 

 Flabellaria is revived for the reception of Udotea Desfontainii and U. 

 minima : and Rhipilia is not only revived, but receives two new species. 

 Other new species belong to Chlorodesmis, Avrainvillea, and Udotea. 

 The relationship of the various genera is treated in the introduction, 

 and the views of the authors are set forth in tabular form. Hitherto the 

 genera of Codiaceas have been divided into Codieas and Udotea? ; but the 



* Verh. Schweiz. Naturf. Gesell., i. (1910) pp. 254-5. 



t Proc. Linn. Soc. New South Wales, xxxv. (1910) pp. 459-95 (4 pis.). 



X Bull. Soc. Hist. Nat. du Doubs, No. 16 (Mai-Decembre, 1908). 



§ ' Siboga ' Expeditie, Monog. lxii. Leiden : Brill, 1911, 150 pp. (22 pis.). 



