[Vol.. 2 



420 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



view of the genetic relation to Rhizoctonia as improbable; 

 and Saccardo, who at first accepted the relationship, subse- 

 quently changed his opinion. Prunet ('93) states that he 

 made certain inoculation experiments from which he was con- 

 vinced that Fuckel was correct; but we possess no indica- 

 tions as to how these experiments were conducted. The 

 writer in 1899, at Leipzig, germinated the spores of Lepto- 

 sphaeria circinans and obtained a mycelium bearing no re- 

 semblance to the Rhizoctonia hyphae. The idea that Lepto- 

 sphaeria constitutes a perfect stage of the Rhizoctonia has 

 had no support recently, although Comes ('91) incorporates 



extreme form in his treatment of 



5 



Rostrup ( '86) found in the spring on the old roots of af- 

 fected plants a pycnidial stage which he considered to be con- 

 nected with the Rhizoctonia hyphae; and on the old roots of 

 Ligustrum he found reddish filaments and scattering peri- 

 thecia; the latter he identified as a species of Trichosphaeria. 

 His assumption, however, has received no encouragement. 

 When Hartig ('80) discovered a Rosellinia as the perfect 

 stage of his Rhizoctonia Quercina there was a temporary re- 

 vival of interest in the quest for one of the Ascomycetes as 

 the perfect stage of R. Cvocorum. 



Frank ('97) reported observing the violet fungus on the 

 grape, and associated with it he found a species of the The- 

 Jephoraceae. This he regarded as the perfect stage, and to the 

 fungus he applied the name Thelephora Rhlzoctoniae. This 

 observation has failed of confirmation. 



Eriksson ('13) has recently presented an extension of his 

 earlier account ('03 a ) of diseases produced by Rhizoctonia, 

 and in this he records a new "Hypochnus," H. violaceus 

 (Tul.) Eriks. as the perfect stage of "Rhizoctonia violacea, 

 Tul." In this he was stimulated by the observations of Rolfs 

 ('03) and others in America, and Pethybridge ('11) in Ire- 

 land, on the occurrence of the basidial stage (Corticium 

 vagum B. & C. or Hypochnus Solani Prill. & Del.) of Rhizoc- 

 tonia Solani Kiihn, resulting in a reexamination of some ma- 

 terial of the violet fungus on roots and stems of certain wild 

 plants. This material had been preserved in alcohol thirteen 



