ZOOLOGY AND BOTANY, MICKOSUUPV, ETC. 299 



a transverse division occurs. The segmeuts, enlarging more rapidly 

 below than al)ove, cause the eversion of the cylinder. 5. In the rhizome 

 the segments of the apical cell divide transversely first, and later irregu- 

 larly, and the upper and lower portions of a segment enlarge uniformly. 

 C. The vascular tissue of the rhizome is produced Ijy the apical cell 

 directly, and is not made up of leaf traces. 



Morphology of Pteridophyta.* — L. K. Rosenvinge pubhshes a text- 

 book of cryptogamic botany, in which he includes a general account of 

 the morphology and reproduction of the Pteridophyta, with a systematic 

 survey of the orders and families. Fossil types are included, and a short 

 chapter is given to Cycadofilices. The text is in Danish, and is 

 illustrated with numerous figures. The volume is an offshoot of 

 E. TVarmiui^'s Systematiske Botanik. 



Bryophyta. 

 (By A. Gepp.) 



Morphology of Bryophytes.f— L. K. Rosenvinge publishes a text- 

 book of cryptogamic botany, in which he includes a general account of 

 the morphology and development of the Bryophyta, with a systematic 

 survey of the orders and families. The work is an offshoot of E. 

 Warming's Systematiske Botanik. The text is in Danish, and contains 

 an altundance of figures. 



Discoloration of Cell-membrane in Polytrichum by Alkali.! — 

 K. von Schoenau publishes the first of a series of studies on Mosses, 

 in which he discusses the coloration of the Polytrichacea? in solu- 

 tions of alkaline reaction. His results are as follows : 1. Solutions 

 of alkaline reaction applied to Polytrichacese turn the leaves an intense 

 brown, owing to the discoloration of the tannin present in the cell- 

 membranes l)y oxidation. This phenomenon produces no harm to t'ne 

 cell, as is seen by its normal contents, the onset of plasmolysis, and 

 the power of the browned leaves to form adventive shoots. 2. The 

 Polytrichaceffi are in general very sensitive towards alkalis ; too strong 

 an alkaline reaction of the solution leads to the death of the plants. 



3. Solutions with an acid reaction prove, as a rule, much less harmful : 

 as a result of acid treatment Polytricha fade to a pale yellow colour. 



4. Polytricha, Hke Sphagna, show an acid reaction. 



Culture of Mosses. § — P. Janzen describes his results in the growing 

 of mosses from the spore. Twenty difTerent species were sown, and of 

 these a sufficient number germinated and matured to add fresh facts 

 and to confirm previous beliefs. He describes methods of culture and 

 media. It is hoped that certain difficulties in the taxonomy of mosses 



* Sporeplanterne (Kryptogamerne). Kjobenhavn: Gyldendalske Boghandel, 

 1913, pp. 310-75 (figs.). 



+ Sporeplanterne (Kryptogamerne). Kjobenhavn: Gyldendalske Boghandel, 

 1913, pp. 268-310 (figs.). 



; Flora, V. (1913) pp. 246-61 (1 pi.). 



§ Ber. Westpreuss. Bot. Zool. Verein, xxxv. (1912) 62 pp. (21 figs.). 



