518 SUMMARY OF CUKRENT RESEARCHES RELATING TO 



filaments penetrated deeper down. Symbiosis induces more active 

 growth in the alga with a kind of yeast-budding of the cells. Tests 

 were made of the relative dampness of rocks containing lichens and 

 those that were lichen-free. In the former case water was absorbed 

 more freely and retained much longer than in the barren rock. 



Lichens of Southern California.* — H. E. Hasse has made a pro- 

 longed study of the lichens of this region, chiefly of those in the county 

 of Los Angeles. The present paper is a resume of work done and pub- 

 lished on these lichens both by himself and by other writers who have 

 aided him during many years, as for instance Nylander, Stizenberger, 

 and more recently Zahlbruckner. A sketch is given of the topography 

 of the district, which includes coast, mountain, and desert. Lichens are 

 well represented except in the desert, where the few species are chiefly 

 terrestrial or saxicolous, corticolous forms being rare ; the prevailing 

 often severe dust and sand storms affect adversely the lichen growth. 

 Diagnoses of all the species recorded are published by Hasse with locality. 

 Synoptic keys are provided of genera and species. 



Mycetozoa, 



(By A. LoRRAiN Smith, F.L.S.) 



Notes on the Mycetozoa of Linnaeus. f — Following the decision of 

 the International Botanical Congress of Brussels to refer the momen- 

 clature of the Mycetozoa back to Linnaeus, G. Lister has examined not 

 only the published accounts of species, but the plants preserved in the 

 Linnean herbarium. 



The species described by Linnaeus were included under various 

 fungus genera : Clathriis, Lijcoperdon, and Mmor. On the herbarium 

 sheets four specimens of " Glathrus " were forms of Stemonitis. Under 

 Lycojwrdon had been placed species of Diderma, Lycogala, and Trichia. 

 The writer gives an account of the microscopic structure of the various 

 species examined. 



History of the Study of Mycetozoa. | — G. Lister, in her Presiden- 

 tial address to the British Mycological Society, has given an historical 

 account of our knowledge of these organisms from the first references 

 by Tourncfort, who described a " puff-ball " that was probably Lycogcda 

 and Jean Marchant, who gives an account of " the Flowers of Tan," 

 down to the present day. Full justice is done to the various writers at 

 each stage of scientific progress. To De Bary is due the modern con- 

 ception of fungus-animals or Mycetozoa, though for long they were con- 

 sidered to be purely fungoid, and are still frequently described as 

 Myxomycetes or slime-fungi. 



* Contr. U.S. Nat. Herb. Washington (1913) xii and 132 pp. 



t Journ. Bot., li. (1913) pp. 160-4. 



: Trans. Brit. Mycol. Soc, iv. (1913) pp. 44-61. 



