Seaver: Studies in Pyrophilous Fungi 139 



Explanation of Plates 

 Plate IX 



Two pots of soil, the left unsterilized, the right sterilized with dry heat 

 at 140 0 C. for 15 hrs. Both were planted with seeds of pea, the sterilized 

 pot soon becoming thoroughly infected with Pyronema omphalodes (Bull.) 

 Fuckel, the unsterilized pot remaining uninfected. X §. 



Plate X 



Soil cultures, the left unsterilized, the right sterilized with steam under a 

 pressure of 5 lbs. for 1-2 hrs. Both were innoculated with the spores of 

 Pyronema omphalodes at a point near the center of the culture. The 

 unsterilized culture produced no fruit and a very scant growth of mycelium 

 surrounding the point of inoculation. The sterilized culture produced an 

 abundant growth of mycelium and abundant fruit. X h 



Plate XI 



Soil cultures, the left sterilized with dry heat at no° C. for 1 hr., the 

 right sterilized at 145 0 C. for 1 hr., the latter producing mycelium and fruit 

 in much greater abundance than the former. X£. 



Plate XII 



1-2. Germination of spores of Pyronema omphalodes in hanging culture 

 after 20 hrs. 



3. Portion of mycelium drawn from culture grown on agar. 



4. Portion of a cluster of oogonia at an early stage. 



5. Cluster of oogonia drawn from material grown on agar. 



6. Cluster of oogonia partially teased out. 



7-13. Figures of oogonia and antherida drawn from material grown on 

 agar. 



14-15. End views of oogonia and antheridia drawn from 'culture material. 



All the figures on this plate were sketched with the aid of a camera 

 lucida, and are magnified 500 diameters. 



New York Botanical Garden. 



