50 THE MYXOMYCETES 



subsist largely on fungi and bacteria. Lister early noted that 

 Badhamia iitriciilaris can attack living species of Corticium. 

 Skupienski (1920) recorded the fact that Didymhim difforme 

 utilizes the spores of such common molds as Aspergillus and 

 Penicillium, as well as yeasts and bacteria. Gilbert (1928b) sup- 

 plied the swarm cells of twenty species of Myxomycetes with 

 spores of certain Agaricaceae, Polyporaceae, Mucorales, Pyreno- 

 mycetes, Discomvcetes, and Fungi Imperfecti, and found that 

 ali could be used by each of the slime molds, provided that the 

 spores were not too large to be engulfed by the swarmer. He 

 used Arcyria demidata, A. incarnata, Badhamia magna, B. lilacma, 

 Comatrichia typhoides, Dicty diaethalhim plinnhemn, Didymhim. 

 mgripes var. xajithopiis, Enteridiiim splendens, Fidigo septica, 

 Hemitrichia clavata, H. vespariiim, Leo carpus fragilis, Lycogola 

 epidendnim, Fhysanim viride, Reticidaria lycoperdon, Stemoiii- 

 tis jerniginea, S. jiisca, S. splendejis var. flaccida, and Trichia 

 fioriforims. 



Howard and Currie (1932) grew various agarics and polypores 

 on agar media fortified with decoctions of corn, rolled oats, pota- 

 toes, or Vicia faba and found that 2 1 species of slime molds were 

 parasitic upon the mvcelia of the various Hymenomycetes. 



By making a series of motion pictures of feeding plasmodia at 

 inten^als of 5 to 10 minutes and then projecting them at the usual 

 rate, Howard was able to show that the plasmodium flows and 

 recedes as do the waves on a beach, and in so doing breaks into 

 fragments the fungal hvphae or hymenomycete sporophores 

 upon which it is feeding. 



Artificial culture. Several methods have been devised 

 whereby slime molds can be grown and maintained in artificial 

 culture. Many workers have cultivated them on the sporophores 

 of Hymenomycetes. Howard (1931) noted that Fhysanim poly- 

 cephahnn could digest a large pileus of Ajnanita imiscaria within 

 24 hours. He utilized oat agar as a medium for artificial cultures, 

 placing near the edge of the dish a fragment of plasmodium of 

 F. polycephalum. After the plasmodium migrated from its origi- 

 nal place of lodgment, a fragment was transferred to another 

 dish, and by means of several transfers the plasmodium was essen- 

 tially freed from contaminants. Camp (1936) placed the plas- 

 modial or sclerotial fragments of this same species on a gauze or 



