C92 SCIENTIFIC RECORD FOR 188S. 



described by E. M. Holmes iu Grevillea. Piccone has published an ac- 

 count of the algse collected in the cruise of the " Volante" in the Mediter- 

 ranean. In an interesting paper on the flora of snow and ice, especially 

 in Arctic regions, Wittrock gives an account of the forms known to 

 occur in such regions, with notes and figures of the development of 

 Sphcerella (Protococeus) nivalis. Lagerheim read a paper on the snow 

 flora of Lapland before the Botanical Society of Stockholm. Lundell 

 states that he has found Desmids in a living condition in blocks of ice. 

 In Pringsheim's Jahrbiicher A. Fischer bas a paper on the occurrence 

 of gypsum crystals in Closteria, and in the Bot. Zeitung a detailed ac- 

 count of the cell division iu Closteria. Additions to British Desmidiem 

 are given by Joshua in Journal of Botany. Parts 11 and 12 of Wit- 

 trock and Nordstedt's Algce Scandinavicm appeared this year. Two new 

 series of alga} exsiccatas have made their appearance — a British series 

 of marine species by E. M. Holmes, and a French series of fresh-water 

 species by Mougeot, Manoury, and Koumeguere. 



Diatomacece. — Two very elaborate papers by Otto Mueller have ap- 

 peared. The first is on the Law of the Successive Cell Divisions ofMclosira 

 arenaria, and appeared in the Bericht. Deutsch. Bot. Gesell. The second, 

 in Pringsheim's Jahrbiicher, has a similar title, and is in fact an extension 

 of the last-named paper, with ample illustrations. He gives diagrams 

 of the divisions of tbe cells by two's and three's, showing how provision 

 is made for retarding the diminution in size of the cells to such a de- 

 gree that further increase cau only take place by the formation of 

 auxospores. The cell divisions of Synedra ulna have been studied by 

 Schaarschmidt. Numerous papers have been written on the cause of 

 locomotion in diatoms, but the writers differ widely on this point. A 

 paper by Eugler on pelagic diatoms of the Baltic was read at the an- 

 nual meeting of German naturalists. Lanzi has given a short account 

 of the diatoms of Lago di Bracciano, paying particular attention to the 

 floating forms. Prinz and Ermenghem have been able to make out 

 some obscure points in the structure of the valves of diatoms by means 

 of sections of what is known as the Cementstein of Jutland. The 

 Synopsis des Diatomees de Belgique of Van Heurck has been continued, 

 and series 1 and 2 of Grunow's notes and determinations of this 

 work have been published. The diatoms collected during Nares's Arctic 

 expedition have been described by Oleve in the Jour. Linn. Soc, and 

 those collected on the Vega expedition have been published in the re- 

 ports of the expedition, also by Cleve. 



Characece. — Dr. T. F. Allen's Notes on the American Species of Tolypella, 

 in the Torrey Bulletin, has full descriptions of six species, with numerous 

 illustrations. Henry and James Groves have notes on British Characecv 

 in the Journal of Botany ; a description of a new species, Chara soco- 

 trensis, is giveu by Nordstedt in the Bericht. Deutsch. Bot. Gesell. ; and 

 Spegazzini describes a considerable number of Characece from the Ar- 

 gentine Kepublic, several of which are new, in Characece Platenses. 



