142 FUNGI AS ANTAGONISTS 



growth of fungi. The active substances produced by these organisms 

 show considerable selective action just as in the case of the bacteria. 

 Actinomycin was found (945) to inhibit the growth of Penicillium, 

 As-pergilliSy Ceratostom-ellay and yeasts in concentrations of i : 50,000 j 

 larger amounts (1:10,000) were required to inhibit other fungi, in- 

 cluding Rhizofus and Trichoderma. Streptothricin is less effective 

 against fungi, although it inhibits the growth of certain yeasts (1002). 

 A comparison of the fungistatic activity of several antibiotic substances 

 upon the causative agent of Dutch elm disease is brought out in 

 Table 31. 



ACTIVITY OF FUNGI AGAINST INSECTS AND 

 OTHER ANIMAL FORMS 



A number of fungi are capable of parasitizing insects and other ani- 

 mal forms. Comparatively little is known concerning the production 

 of antibiotic substances by these animal parasites. 



