Prodac .fungi i6 



to be examined for fungi in the middle of agar plates and leave it to 

 fester for quite a long time. It gets into a disgusting state, full 

 of mites, eelworms, and so on. Then I observe under the dissecting 

 microscope if there are predacious fungi present. They will be seen 

 pushing up erect conidiophores with the saores at the end. I take a 

 very small piece of agar on the tip of a sterile needle and simply 

 pick off the spores individually until the agar is filled. It is 

 very simple and effective. 



For recovery of the fimgi from soil, I use another method. I take a 

 little of the soil and place it in the bottom of a sterile petri dish. 

 I put in with it a small piece of an agar culture of saprophytic nema- 

 todes. Then I pour sterile rabbit dung agar onto this, after having 

 first allowed the agar to cool nearly to the temperature at which it 

 jells. I shake the dish a little to distribute the soil. The eel- 

 worms from the small peice of agar culture serve to supply prey in case 

 nematodes are deficient in the soil. In this way, one easily gets 

 predacious fimgi from the soil. They are then isolated for subcultures 

 in the way previously mentioned. 



Q. Do you find these fungi in certain types of soil? 



A. I find them very commonly in nearly all types of soil. I have 



looked at a great many soil plates, but I would not care to attempt 

 drawing any conclusions as yrt. One would have to examine many thou- 

 sands of soil isolation plrdes before he could get enough data on which 

 to generalize about which i.oils they occur in specifically or most 

 abundantly. I will merely s ay that I have found them in nearly all 

 types of soil. There are tvo types of soil from which I have failed to 

 get these fun<^i, the very acidic peat and very sterile mineral soil. 



Q. How of+"n do you find the fungi rapturing plant-parasitic nema- 

 todes in the soil? 



A. I have never myself made direct observation of them capturing plant- 

 parasitic nematodes, probably because I am, I am afraid, unable to 

 identify the nematodes. Dr. Goodey has recorded an Arthrobotrys captur- 

 ing the stem eelworm on wheat. 



Q. Is there any evidence of attraction of the nematodes to the trap- 

 ping organs, or is it piirely chance that the nematodes come in con- 

 tact with them? 



A. I have never seen any evidence of attractiveness. I think it is 

 purely chance. 



Q. Have you ever observed fungi in the genus Fusarium attacking nema- 

 todes? 



A, No, not yet. I have found that there are some Fusaria that attack 

 the contents of nematode cysts. 



