ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 147 



Remarkable Symbiotic Algse.* — J. Schiller describes a new 

 departure among algaj in tlie form of a Siphonaceous species which is 

 entirely devoid of chlorophyll, has a cell-membrane which contains 

 chitin, and lives in symbiosis with Nostoc symbiotu-um, a new species. 

 It was found by F. von Wettstein in a cabbage-field in Upper Austria, 

 and called by him Geosiphon pyriforme. It forms an analogy to the 

 lichens, and may lead to an understanding of the connexion between 

 the formation of chitin and organic nutrition. 



Development of Griffithsia corallina.f — H. Kylin describes in 

 detail the structure of the shoot of Griffithsia, the division of vegetative 

 cells and nuclei, development of the procarp till it is ripe for fertihzation, 

 and after fertilization, development of cystocarps, spermatia and 

 tetraspores. The somatic nuclear. divisions follow the same course as 

 in Rhodomela virgata. The female branch bears in G. corallina 

 two procarpia, in G. Bornetiana one. The carpogone of Floridete 

 appears often to have two nuclei. Of the procarpia, often only one 

 develops into a gonimoblast. The carpospores are always uninucleate. 

 After fertilization the guard-cells begin to develop ; they are formed 

 from the first central cell (the basal-cell) of the female branch, and 

 consist of two cells. The upper one is the guard-cell proper, the 

 lower one represents a connecting cell between the guard-cell and the 

 basal cell of the branch. The spermatangia are formed on very much 

 branched tults, which grow in a crowded mass between two cells of the 

 main branch. The lower cells of the main brauchlets are multinucleate, 

 the upper ones uninucleate. The apical cells of the developed male 

 branches represent the spermatangia mother-cells, which cut off two to 

 three spermatangia. The primary tetrasporangia nucleus possesses, like 

 the other cell-nuclei of the tetraspore plant, a distinct nucleolus and a 

 network with many small chromatin grains. Spireme stages occur in 

 the reductions-division of the tetrasporangia nuclei in G. corallina. 



Oceanic Algae. J — A. Mazza, continuing his studies of oceanic 

 algology, discusses the Squamarieae, comprising the genera Gruoriopsis, 

 Cruoriella, Feyssomielia ; also the Ha^matophloefe, with the genus 

 Hsematocelis, with the somewhat doubtful allies Rhododermis, Erijth.ro- 

 dermis, Rhodophysema, etc. The morphology and structure of one or 

 more species in each genus are described. In the case of Peyssonnelia 

 sixteen species are thus treated, one being the type of the sub-genus 

 Ethelia. 



West Indian Marine Algae. §—F. Borgesen continues his report on 

 the marine algse of the Danish West Indies. In the present contribution 



* Die Naturw., iv. (1916) pp. 78-80. See also Bot. Centralbl., cxxxii. (1916) 

 p. 409. 



t Zeitschr. f. Bot., viii. (1916) pp. 97-123(1 pi. and figs, in text). See also Bot. 

 Centralbl., cxxxii. (1916) pp. 431-2. 



X La Nuova Notarisia, xxviii. (1916) pp. 169-215. 



§ Marine Algse of the Danish West Indies. Copenhagen : B. Luno, ii. (1916) 

 pp. 81-144. 



L 2 



