19151 



DUGGAR — RHIZOCTONIA CROCORUM AND R. SOLANI 421 



years earlier. The result of his study is reported as follows : 



"D'apres ces renseignements, il faut — du moins pour ce qui 

 concerne les formes du champignon qui envahissent les Car- 

 rottes — considerer comme resolue la question tant debattue de 

 savoir a quel groupe rapporter le mycelium sterile connu sous 

 le nom de Rhizoctonia violacea. Dans ce qui suit, je vais in- 

 diquer le nom scientifique qu'il faut donner, ainsi que les car- 

 acteres diagnostiques du champignon autant que j'aie pu en 

 juger sur les documents conserves que j'avais a ma disposition." 



On the basis of these observations he creates the Hypochnus 

 mentioned. No adequate diagnosis is given, but the im- 

 portant part of the account is as follows : 



"Ensuite le champignon forme autour des tiges de la meme 

 plante ou d'autres especes de plantes immediatement au-dessus 

 du sol, une enveloppe annulaire, membraneuse, d'un rose tendre, 

 qui, montant souvent sur les tiges jusqua une hauteur de 5 a 

 15 mm. et s'etalant parfois sur la surface du sol comme une 

 feuille toute mince, produit des basidiospores. C ? est le stade 

 Hypochnus/' 



This apparently refers to material on Stellaria media, Myo- 

 sotis arvensis, Galeopsis Tetrahit, Erysimum cheiranthoides, 

 Urtica dioica, and Sonchus arvensis, which hosts he would 

 regard as harboring the Hypochnus stage of that form of the 

 violet fungus attacking the carrot, and for this reason the 

 names just given appear in the list of hosts. 



In the writer's opinion he properly considers it remarkable 

 that the fructification stage should attack hosts other than 



prod 



In view of the character of 



the material, the incompleteness of the account, and the pos- 

 sibility of confusion with Corticium vagum B. & C. it would 

 appear necessary to await confirmation of the observation 

 that a Corticium (Hypochnus) may represent the perfect 

 stage of the fungus here discussed, although, reasoning from 

 the apparent relationship of this species to R. Solani, a 

 Corticium stage might well be assumed. The writer has been 



unable thus far to secure any of the material mentioned. 



In a footnote Eriksson expresses himself thus: " Quant 

 la Rhizoctone de la Luzerne, je suis norte a croire. d'anres 1 



