ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 109 



introduction, the structure of Mosses in general is described under 

 seven beads, viz. (1) tbe protonema, (2) the stem, (3) tbe leaf, (4) tbe 

 sexual organs, (5) tbe inflorescence, (6) tbe sporogonium, and (7) tbe 

 vegetative mode of reproduction. The Musci are divided, in the first 

 place, into four orders : Si^bagnaceaB, AndreseaceaB, Archidiacefe, and 

 Bryineae ; the last again into two tribes, Cleistocarpae and Stegocarpfe, 

 and tbe latter of these into two sub-tribes, Acrocarpae and Pleuro- 

 carpje. Of S])hagnum, the sole genus of Sphagnacege, twenty-three 

 species are described. In tbe Andreaeacefe are comprised nine species 

 of Andrecea; in tbe Arcbidiaceee the single species Archidium 

 pJiascoides. 



Algae. 



Assimilating' System of Algae.* — Although in even the higher 

 algfe (sea-weeds) there is no distinct differentiation of the structure 

 into epidermal, assimilating, and conducting tissues, still, according 

 to Herr N. Wille, there are cells which are esj>ecia]ly concerned in 

 assimilation, and which may be either iso-diametrical or elongated in 

 a direction either parallel to or at right-angles with the axis. Such 

 an assimilating-system he classes under three heads, and eighteen 

 types, viz. — (1) An assimilating-system which acts also as a con- 

 ducting system ; to this belong three types ; viz. those of Ulva, 

 PohjsipTionia, and Lithoderma ; (2) An assimilating distinct from a 

 conducting system: either a, conducting system imperfectly developed, 

 including seven types, viz. those of Bliodomela, Dictyota, Ceramium, 

 Corallina, Ahnfeltia, and a type with organs which, from a physiological 

 point of view, are leaves, viz. Myriactis and Batrachosjpermum ; 

 b, conducting system well developed, with four types, viz. Desmarestia, 

 Chorda, Chordaria, and Furcellaria ; and (3) in addition to an assi- 

 milating system, there is both a primary and a secondary conducting 

 (Leitungs and Zuleitungssystem) system : —four types, viz. those of 

 Nothogenia, BhodophyUis, Cryptosiphonia, and Halimeda. 



Algae from Madagascar, f — In a collection of algfe made by 

 M. Ch. Tbiebaut from Majunga in the north-east of Madagascar, 

 Tamatave, and tbe coast of the same island opposite Reunion, and 

 described by M. E. Bornet, he records a new species of Floridefe, 

 Constantinea ? Thiebautii. 



Fresh-water Algae of Rome. J — Sig. E. Martel enumerates the 

 fresh-water algae of Eome and tbe Campagna. Of Floride83 only one 

 species is described — Hildebrandtia rividaris. Of Chlorosporeje there 

 are fifty-five, including a new genus of Palmellacese, CJdoroihecium 

 Borzi, belonging to tbe Sciadiaceas, but distinguished from all the other 

 genera of tbe family by its dimorphic cells. Tbe purely vegetative cells 

 of the first generation are ovoid ; those destined to produce 1, 2, or 4 



» Bot. Sallsk. Stockhobn, April 22, 1885. See Bot. Centralbl., xxiii (1885) 

 pp. 264, 296. 



t Bull. Soc. Bot. France, sxxii. (1885) pp. 16-19 (2 figs.) 

 i Anu. Istit. Bot. Roma, i. (1884) pp. 182-204. 



