334 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Thallophyta. 



Algae. 



(By Mrs. E. S. Gepp.) 



Phylogeny of Algae.* — J. P. Lotsj publishes a series of lectures on 

 Botanical Phylogenj, delivered by him in the Universities of Leiden 

 and Utrecht. The work is to be completed in three volumes ; the first 

 of these deals with the Algse and Fungi. The author begins with a 

 general genealogical tree of the entire plant world, starting from the 

 common origin Protomastigina, and, working through various groups, 

 arrives finally at Mysomycetes, Fungi, Flagellatfe, Charophyta, and 

 Spermapliytii. The details of these main lines of development are 

 worked out step by step in the text, so far as algge and fungi are con- 

 cerned. The book is plentifully illustrated, and lists of literature 

 applying to each lecture are given at the end of the work. 



Morphology of Lower Algae.t — G. Nadson publishes a preliminary 

 communication on this subject, in which he deals with three points : 

 1. On alterations in Stkhococcus baciUaris Nag. caused by necessities of 

 nutrition. 2. Formation of endospores in SUchococcus baciUaris Nag. 

 and Chloroidium Kriigeri {Chlorothecium sacckarophilum Kriiger) Nads. 

 ?). Chlorobium limicola Nads., a green chlorophyllous microbe. In the 

 first note the author details tlie effect of certain nutritive solutions on 

 cultures of Stichococcus baciUaris, and points out that the different forms 

 assumed by this species have been regarded by authors as representing 

 other species and even genera. The formation of endospores in pure 

 cultures occurred as the result of unfavourable conditions of life. The 

 cell-contents (either all or a part) shrivel up and form a colourless endo- 

 spore, which surrounds itself with a membrane. When germination 

 takes place the spore swells up, and, without throwing off the membrane, 

 becomes gradually a young algal cell. Li Chloroidium Kriirjeri the new 

 chromatophore is not developed from the leucoplast, but arises by a con- 

 densation of part of the protoplasm, at the same time becoming green. 

 The paper is in Russian, with a German resume. 



Germinating Plantlets of Florideae.:}:— F. Tobler gives a short 

 account of the germination of some of the Florideae. In the material 

 which he has examined he distinguishes three types : (1) The upright 

 type of Ceramio-Rhodomelege ; (2) the disk or horizontal type ; (3) 

 the hemispherical type. The species here described in detail are 

 Griffithsia opantioides, Plocamium coccineum, Gigartina Teedii, Poly- 

 siphonia urceolata, and F. variegata. Griffithsia belongs to the simple 

 Ceramium type, but the other three genera are more complicated. One 

 feature, however, is common to all three, and that is that at some given 

 moment sooner or later, a process of active cell-division takes place with- 

 out any special increase in size. A more or less shapeless mass of cells 

 is formed, and from this a shoot arises ; the cell-mass does not itself 



* Vortriige iiber Botan. Stammesgescbichte. Jena : Fischer, i. (1907) iv. aud 

 828 pp. t Bull. Jard. Imp. Bot. St. P^tersbourg, vi. (1906) pp. 184-94. 



: Beih. Bot. Centralbl., xxi., Ite Abt. (1907) pp. 148-55 (1 pi.). 



