ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 215 



Hair-like Growths of the Rhodomelaceae.* — L. K. RosenvLnge 

 has made a special study of these organs, which he calls trichoblasts, 

 on the thallus of Rhodomelacere, and describes his results under seven 

 different headings : — (1) branching of the trichoblasts ; (2) tricho- 

 blasts of aberrant structure ; (3) function of the trichoblasts ; (4) are 

 there any species of Polysiphonia without trichoblasts ? (5) forms 

 intermediate between stems and trichoblast ; (6) position of the sexual 

 organs in Rhodomela ; (7) communication between the basal cell of the 

 branch with the trichoblast, in Polysiphonioe with axillary shoots. The 

 mode of ramification is essentially the same throughout the order, but 

 the degree of branching varies considerably, sometimes even in the 

 same species. Several functions have been assigned to these trichoblasts 

 by various authors, but Rosenvinge is inclined to believe they serve for 

 absorption or respiration. Although it has been stated that certain 

 species of Poly siphon ia are without trichoblasts, it is here shown that 

 every species possesses at least fertile trichoblasts. Sterile trichoblasts 

 are capable of being transformed into stems. The sexual organs of 

 Rhodoinelacese are more generally attached to the trichoblasts than has 

 been admitted by Falkenberg. The paper closes with some interesting 

 remarks on the pores between contiguous cells. 



Lithothamnia from the Indian Ocean.f — M. Foslie publishes a 

 report on the species of Lithothamnia collected by J. Stanley Gardiner 

 during his Expedition to the Maldive and Laccadive islands in 1899- 

 1900. The species are nine in number, and constitute the first authentic 

 record of these algae between the Red Sea and the East Indies. General 

 observations are made on the distribution of Lithothamnia and on the 

 conditions of their growth. The author finds that Lithophyllum 

 craspedhim plays a prominent part in reef -building in general, and is 

 therefore well represented in certain atolls of the Maldives, at Funafuti, 

 and at Onoatoa, Gilbert islands. Goniolithon frutescens is the next 

 most abundant species in the Maldives, and LitlwphyUum oncodes 

 appears to act as a kind of cement. Three new forms are described 

 of species already existing, and critical remarks are appended to each 

 species' name. Two large plates give reproductions of most of the 

 species in natural size. 



Marine Algae of Iceland. $— H. Jonsson publishes Parts III. and IV. 

 of this Flora, consisting of Chlorophyceae and Cyanophycese respectively. 

 Critical and interesting notes are appended to the species-names, and 

 there are nineteen figures in the text, to show various details of structure 

 described. Acrosiphonia flabelliformis is described as a doubtful new 

 species. The Cyanophycese, six in number, were determined by 

 J. Schmidt. 



Marine Algae from Sicily.§— A. Mazza publishes the first part of 

 a list of marine algae from this island, with critical notes on many of 

 the species. The plants recorded were either gathered by himself or 



* Overs, k. DaDsk. Vidensk. Selsk. Forh., 1903, pp. 439-71 (16 figs, in text), 

 t Fauna and Geogr. Maldive and Laccadive Arckip., ed. J. S. Gardiner, i. (1903) 

 pp. 460-71 (2 pis.). % Bot. Tidsskrft., xxv. (1903) pp. 337-81 (19 rigs.). 



§ Nuov. Notar., xv. (1904) pp. 5-30. 



