ZOOLOGY AND BOTANY. MICROSCOPY. ETC. 399 



SteasiSBB, P. Pius — V. Nachtrag zur Pilzflora des Sonntagberg (Nied.-Oest.). 

 (Contribution to the fungus-flora of the Sonntagberg, Lower Austria). 

 [The list includes the Tuberacese and Pvrenomvcetes, Nos. 1653-1774.] 



Arm. MycoL, ix. (1911) pp. 74-93. 



Thbiszen, F. — Die Hypocreaceen von Rio Grande do Sul, Sudbrasilien. (The 

 Hypocreacese of Rio Grande do Sul, S. Brazil.) 



[Description of the family, genera, and 103 species.] . 



Tom. tit., pp. 40-73 (8 pis.). 



Wehmeb, C. — Notiz iiber Khizopus-Arten. (Note on species of Rhizopus.) 

 [Bv culture experiments, the fungus was accurately determined.] 



Ber. Deutsch, Bot. Ges., xxviii. (1911) pp. 547-9. 



Westling, R. — En ny ascusbildende Penicillium-Art. (A new ascus-forming 

 Penicillium. 



[The fruiting-form of a new species was found, and is described.] 



Sv. bot. Tidskr., iv. (1910) pp. 139-45 (1 fig.)- 

 See also Bot Centralbl.. cxvi. (1911) p. 212 



W held on, H. J. — Some Argyll and Perthshire Fungi. 

 [Fungi collected during a tour in North Scotlaud.] 



Arm. Scot. Nat. Hist. (1911) pp. 34-8. 



Wo bo xow, G. — Contributiones ad Mycofloram. Caucasi. (Contributions to the 

 fungus-flora of the Caucasus ) 



[A list of 368 species.] Truth a. d. Bot. Gart. Tiflis, xi. (1910) pp. 133-71. 



See also Ann. Mycol., ix. (1911) p. 128. 



Lichens. 



(By A. Lobrajn Smith.) 



Lichen Gonidia.* — F. Elfving recounts the history of the contro- 

 versy as to the nature of the various elements of the lichen thallus. 

 Schvvendener, followed by Bornet, insisted that it was composed of two 

 sepante organisms— alga and fungus — living together in symbiotic 

 relationship and without genetic connexion. Their views gradually 

 prevailed, and are now universally accepted. Elfving considers that 

 there is room, however, for reconsideration, and describes his research 

 on several typical lichen thalli. In Peltigera canina the gonidia lie 

 below the cortical layer. They have been identified as a species of 

 Poli/coccus, considered by Kirchner as a form of Nostoc pwictiforme. 

 They are spherical or ovate blue-green cells, and occur iu groups sur- 

 rounded by hyphae. In the lower and middle parts of the gonidial zone 

 the cells give the impression of being algal, lying free amongst the 

 hyph;e. Towards the cortex they are embedded among the colourle-s 

 cellular tissue as if they filled up hollow places. Closer observation 

 shows that they differ from the colourless cells only by their colour, and 

 form with the others a continuous tissue ; lower in the zone they possess 

 a gelatinous wall. 



Elfving holds that the formation of new cells takes place daring ;i 

 short period in spring. The cortex consists of an outer layer of thick- 

 walled cells that pa^s over into hair-like hyphas. Within this layer lies 



* Forh. Nordisk. Naturf.-och Liik., xvi. 7 Helsingfors (1903) pp. 26-30. 



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