THE FORMATION OF HYPHAL FUSIONS 



21 



strains of Rhizoctonia. Forsteneichner found that in a Rhizoctonia 

 growing on cotton plants in Turkey fusions were common, but that 

 the mycelium would not form fusions with the mycelium of R. 



Fig. 10. — Absence of liyphal fusions between two species of Microsporon. The 

 mycelium of Microsporon audouini from patient C, left unshaded, and the 

 mycelium of Microsporon lanosum from patient E, shaded, which have 

 been growing side by side in a hanging drop of Sabouraud's medium for 

 three weeks, have come into contact with one another, have become 

 interlaced, but have not fused with one another. Hyphal fusions may be 

 observed between two hyphae of M. audouini or between two hyphae of 

 M. lanosum : ///, numerous hyphal fusions, but none of them between 

 a hypha of M . audouini and a hypha of M. lanosum. Drawn by E. S. 

 Doweling. From the paper of Davidson, Dowding, and Buller on Hyphal 

 Fusions in Dermatophytes. Magnification, 347. 



Solani and two other Rhizoctonia strains. Matsumoto and his 

 co-workers found that, in Hypochnus Sasakii, perfect fusions take 

 place between hyphae of one and the same strain, but that only 

 hyphal contacts or imperfect fusions take place between strains less 

 closely related as judged morphologically. They also found that 

 the mycelia of Hypochnus Sasakii and Rhizoctonia Solani do not 



