ENVIRONMENTAL FACTORS 



75 



Solutions. It has been the general experience that the readily 

 cultivable parasitic and hemiparasitic fungi have about the same 

 relation to strengths of solu- n r 



tions as the saprophytic forms. 

 Ordinarily, therefore, such 

 forms give abundant growth 

 under widely different condi- 

 tions of concentration of the 

 substratum. According to 

 Eschenhagen the concentra- 

 tions at \\\\\c\\Botrytis cinerea 

 may grow under ordinary cir- 

 cumstances are as follows : 

 grape sugar, 51 per cent ; 

 cane sugar, 37 per cent; 

 sodium nitrate and calcium 

 chloride, 1 6 per cent ; sodium 

 chloride, 12 per cent. In the 

 culture work in the laboratory 

 it will be found, however, that 



differences in the Strength of FIG. 15. CELLS OF ERICACE.E (after Ter- 

 the culture medium will be netz), AND ORCHIDACM WITH ENDOPHYTIC 



accompanied by noticeable 



differences in the form of the fungous colony, amount of the 



mycelium, and the character of the spores produced. 



