100 SUMMAP-Y OF CURRENT KESEARCHES. 



Relation of Silicicolous Lichens to the Substratum.— E. Bachmann 

 [Ber. Deutsch. Bot. Ges., 1917, 35, 467-76, 8 figs.). The author found 

 that the hyph^ of Lecidea crustidata left no trace on quartz crystals. 

 He noted that the rhizoids of ParrneUa siihaurifera swelled at the base 

 into a somewhat stellate " foot-plate," which consisted of mucilage cells. 

 A hollow space between the foot-plate and the lower surface of the 

 thallus served as a " damp chamber," and therefore the rhizoids of this 

 species serve as water conductors and water storers. A. L. S. 



Relation between Algae and Hyphse in the Lichen-thallus. — 

 W. NiENBURG (Zeitschr. Bot, 1917, 9, 529-43, 1 pi., 6 figs.). The 

 author, while criticizing recent work by Elfving, records the results of 

 his own researches : that algfe are transported within the thallus by 

 " push-hyphae " from the gonidial zone to positions in the cortex ; and 

 also that cases of parasitism occur in Evernia furfuracea. On this 

 account he regards the relationship between the components of the 

 thallus as helotism. A. L. S. 



Botanical Results of the Swedish Expedition to Patagonia and 

 Terra del Fuego, 1907-9. VI. Lichens. — A. Zahlbruckner {Kgl. 

 Sv. Vet.-Akad. Hcmdl, 1917, 15, No. 6, 1-62). The author indicates 

 the sources from which he received the material examined — a few saxi- 

 colous specimens from the Swedish Expedition,' 1901-3 ; P. Dusen'e 

 collection under Nordenskjold ; also those collected by Skottsberg in 

 the 1907-9 Expedition. He describes a large number of species, new 

 and old ; and he gives a tabulated list of all the lichens from the Falk- 

 land Islands. A. L. S. 



Lichens from the Neighbourhood of Hamburg. — J. Erichsen 

 {Verk. Naturw. Ver. Hamburg, 1917, 24, 65-100 ; see also Ann. My col., 

 1917, 15, 509). A description of the more unusual lichens. A large 

 number are new to the district. The author has given a full account 

 of the species, with full biological details. A. L. S. 



Lichens of Dune Rubble at Pelzerhaken.— J. Erichsen {Allgem. 

 Bot. Zeitschr., 1916, 21, 79-85 and 138-16 ; see also Ann. Mijcol, 1917, 

 15, 508-9). The dunes examined are in Holstein. Most of the lichens 

 collected were dark-coloured forms, and were characterized by minute 

 apothecia and spores. Degenerate thalli were fairly frequent. A. L. S. 



Research on Lichens in Polarized Light. — L. Santha {Bot. 

 Kozlem&nyek, 1916, 15, 99-101 and 31-2 ; see also Ann, Mycol., 1917, 

 15, 510-11). The author has examined sections of the thallus of 

 various Physciae under polarized light. He finds curious differences 

 in the amount of light transmitted. Mostly the upper cortex is clear ; 

 the other layers are clear or dark according to the group. He distin- 

 guishes five types, of which the last, the Obscnra group, remains wholly 

 dark. A. L. S. 



