62 Bulletin 186. 



tubes, upon both of which media most forms of Rhizoctonia seem 

 to grow well. In pure culture a loose mycelial growth first appeai-s. 

 This becomes brown in time. A short tufted growth may appear 

 later ; and usually there is also an effuse or crust-like sclerotial 

 development. \\\ culture the sclerotia are usually irregular in form 

 and brown in color. 



At this time it is not desired to enter into a discussion of the 

 slightly different morphological characters which may distinguish 

 the different forms of Rhizoctonia. 



17. — The large, closely septate liypJice loJiicli make up the short tufted growth. 



Brief Notes upon Bhizoctonia in Europe. Historical. 



The root-destroying fungus Rhizoctonia was first discovered by 

 DeCandolle"^ in 1815. He named two species : Rhizoctonia inedi- 

 caginis, occurring on 2fedicago^ Trlfoliuin and related hosts ; and 

 R. crocorum. a fungus destructive to crocus bulbs. Of the brief 

 notes published upon other species of the fungus and other host 

 plants until 1851, a comprehensive summary is given by the brothers 

 Tulasne.f They believed that the several species then described 



*De Caudolle.— Mem. d. Mus. d' hist, nat., 1815. 

 fTulasue, L. etC— Fungi Hypogiiei, pp. 188-195, 1851. 



