1920] CURRENT LITERATURE 359 



that have been described. He also gives a brief synopsis of the factors most 

 prominent in the control of such vegetation, and some of the more important 

 floristic differences which characterize the grasslands at different altitudes. A 

 notable reduction of species is manifest with increase of altitude, the estimate 

 running from 160 species for the mesas, 139 for the foothills, and 107 for the 

 montane, to 50 for the subalpine. A systematic list of species is given with 

 indications of their occurrence at different altitudes. The whole, including the 

 bibliography, forms a most useful contribution, summarizing the present state 

 of our knowledge of these plant communities. — Geo. D. Fuller. 



Biology of Fomes. — White 30 



of the 



enormous 



widely distributed Fomes applanatus, and finds that it attacks practically all 

 deciduous trees and several conifers, causing the destruction of large quantities 

 of wood annually. It produces basidiospores only, which are not of the 

 ordinary type, being "yellow, papillate, thick-walled chlamydospores within a 

 thin hyaline wall." Spore discharge is 

 period than recorded for any other fungus, being continuous day and night 

 , for about 6 months. There was no difficulty in making artificial cultures, 

 and the appearance of the rotted wood makes it possible to distinguish the 

 attack of this fungus from that of any other form. The histological and 

 chemical details of the attack are fully described.— J. M. C. 



Ecology of fungi. — Studying the influence of altitude upon parasitic fungi 

 from collections made by Fragosco in Cataluna, Spain, and by himself in 

 Barreges, Dufrenoy 21 found that the Pyrenees are not a barrier to the dis- 

 semination of fungi, although there are certain differences between the fungus 

 flora of the closely adjacent parts of France and Spain. He concludes that there 

 are species peculiar to the plains and to the mountains, as well as those common 

 to both habitats. The determining factor in altitudinai distribution seems to 

 be neither humidity nor temperature, but radiation. The mountain species 

 are either more highly colored or are found on more highly colored hosts. He 

 was unable to determine any effect of altitude upon the resistance of the 



host.— Geo. D. Fuller. 



Pennsylvania trees. — The fact that within 5 years Illick's" tree manual 

 has reached its third edition is a striking testimony to its excellence. The 

 first part of the volume is devoted to a general discussion of forests, their 

 structure, development, care, and value receiving careful consideration, and 



30 



White, J. H., On the biology of Fomes applanatus (Pers.) Wallr. Trans. Roy. 



Can. Inst. Toronto 1919: 133-174. pis. 2-7. 



21 Dufrenoy, J., Les conditions 6cologiques du developpement des champignons 

 parasites. Etude de geographic botanique. Bull. Soc. Mycol. France 34-8-26. 1918. 



^Illick, J. S., Pennsylvania trees. 3d ed. pp. 235. pis. 1-12Q. figs. 120. Harris- 



burg: Dept. Forestry Penn. Bull. 11: 1919. 



