676 SUMMARY OF CURRENT RESEARCHES RELATING TO 



terminate in hairs which are likewise branched. Growth takes place 

 from the activity of a growing point situated at the point of junction of 

 the th alius and the terminal hair. In the mature th alius three primary- 

 tissues may be distinguished, viz. : — (1) the assimilating-tissue, which is 

 outermost, and consists of 3 or 4 layers of cells ; (2) the intermediate 

 tissue (Fiillgewebe), composed of larger cells, with thicker walls ; 

 and (3) the central cylinder, consisting of only a single row of 

 cells. Of these the second, which constitutes the principal mass of the 

 thallus, gives birth to two new secondary tissues, the hyphal tissue or 

 conducting hyphfe, and an inner assimilating tissue. 



Delamarea, a new genus of Phaeosporese.* — In the Algae collected 

 in the island of Miquelon by Dr. Delamare, M. P. Hariot finds a 

 phaeosporous seaweed, which he makes the type of a new genus, named 

 after the collector, with the following diagnosis : — Thallus cylindraceus, 

 tubulosus, simplicissimus, subcoriaceus, fibris radicalibus affixus, stratis 

 duobus cellularum contextus ; cellulis interioribus majoribus elongatis, 

 versus peripheriam minoribus et brevibus, corticalibus in paranemata 

 inarticulata saccata libera demum evolutis ; sporangia unilocularia ovata, 

 magna, inter paranemata per totam superficiem thalli sparsa ; sporangia 

 plurilocularia. The species described, Delamarea paradoxa, resembles 

 certain Chordariaceee in its fructification and the structure of its frond, 

 but is distinguished by its non-articulated paraphyses. It differs from 

 ScytosipJion in having both multilocular and unilocular sporanges, and in 

 its attachment to the substratum by means of articulated filamentous 

 rhizoids instead of a lobed disc. 



Phseodermatium.f — Dr. A. Hansgirg describes a new genus of fresh- 

 water Pheeophyceee, Phseodermatium, with the following diagnosis : — 



Thallus submembrauaceus, parvus, punctiformis v. plus minus in 

 substrato expaiisus, e cellulis pluristratosis (initio unistratosis) pseudo- 

 parenchymatice cohserentibus constitutus. Cellulae vegetativge rectangu- 

 lares v. polygonse v. subspheericse, in cytoplasmate chromatophorum 

 laminiforme parietale, luteo- v. aureo-fuscescens et guttas (granula?) 

 oleose nitentes includentes, membrana crassiuscula achroa subhomogenea 

 prgeditae. Membrana in mucum gelatinosum mutata, cellulas modo 

 Syngeneticearum in statum palmellaceum transeunt. Propagatio fit 

 bipartitione cellulorum in statu palmellaceo (zoosporge non visse). The 

 only sp., P. rivulare, was found in small streams in Bohemia, attached 

 to a Chantransia and coated with lime. 



Frond of Chordariaceae.^ — According to Prof. F. E. Kjellman, the 

 frond of species belonging to this family of seaweeds, although uniform 

 throughout the family in its mature form, yet belongs, according to the 

 history of its development, to four different types, as represented in (1) 

 Chordaria and Leathesia, (2) ElacJiista, (3) Scytothamnus and Coilodesme, 

 and (4) an undescribed genus from the Japanese seas. 



Distribution of Desniidiace8e.§ — Herr E. Boldt describes in detail 

 the 125 species of desmids found in Greenland, including several new 



* Journ. de Bot. (Morot), iii. (1889) p. 156 (1 fig.). 



t Notarisia, iv. (1889) p. 658. 



t Naturv. Studentsalsk. Upsala, Feb. 9, 1888. See Bot. Centralbl., xsxviii. 

 (1889) p. G97. 



§ Bih. K. Svenbk. Vet.-Akad. Hand!., xiii. (1888) Afd. 3, Nos. 5 and 6, 158 pp. 

 and 4 pis. See Bot. Ccutralbl., xxsviii, (1889) p. 736. 



