Higher Fungi 



85 



Tmu.i: I I. T\i-i.ri-,\cE of Cki,i,uix)se upon tji^o Xvmhkrs ok Fungi in Soil 

 (from Waksman and Starkoy) 



XiiiulxTs |)(-r firaiii of soil. 



NaNOg r 

 React ion Added 



Numbers of Fungi 



Soil Soil with 



of Soil to without 1 Per Cent 



\atiu"e of Soil pW Cultures Cellulose Cellulose 



Unlimed, unmanuml . k 1 - 115,700 160,000 



Unhmed, unmamiml .">. 1 + 115,700 4,800,000 



Limed, umuamu-ed 6.5 - ^20,000 47,000 



Limed, unmanured 6.5 + 20,000 i>!)0,000 



Unlimed, manured 5.5 - 87,300 320,000 



Unlimed, manured ^.') + 87,300 3,100,000 



Higher Fungi 



The occurrence of Basidiomycetes in soil has been studied largely 

 by obser\'ations with the naked eye, and findings are not based upon 

 isolations from soil and cultivation in the laboratory. Hence, only 

 those fungi which produce fruiting stages visible to the naked eye 

 have been reported. Gilbert found that the nature and the concen- 



FiG. 40. Microscopic structure of a soil Aspergillus (from Thorn). 



tration of organic matter in the soil are the most important factors 

 influencing the development of these fungi. Reaction, moisture con- 

 tent, light, temperature, season of year, topography, and nature of 

 higher plants are among the other factors of importance in this con- 

 nection. Some of the organisms are highly specialized, growing 

 only under specific conditions and upon very few organic materials, 

 whereas others are less specific, growing under a great variety of 

 conditions. 



