

19151 



DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 



419 



distances from the plant. Most herbarium material, unfor 



tunately, with 

 include sclerot 



ception of crocus specimens, does not 



In 



a sclerotium consists of f 



compact tissue 



made up of cells often considerably branched and sometimes 

 curiously lobed (fig. 4). 



Fig. 4. Rhizootonia Crocorum: a, from a section of a large sclerotium; 

 b, extreme forms of cells isolated from a macerated sclerotium. 



SUGGESTIONS REGARDING THE PERFECT STAGE 



It has been noted that Du Hamel and other early observers 

 stated that the affinities of the violet fungus were with the 

 truffles. Per 



Sclerotium. 



Fries, and others placed the genus near 

 Tulasne considered the small sclerotia as prob- 



ably a stage in the development of 



(pyreno- 



m 



This suggestion of Tulasne has apparently in- 



fluenced many mycologists, and a search in this direction 



the perfect stage 

 present time. Fu« 



has continued practically until the 

 el suggested that Lanosa nivalis Fr. 



be considered the first or conidial stage of this fungus 



and he believed that the minut 



sclerotia or penet 



cushions gave rise during the latter part of the season to 

 pycnidia. With the more complete disintegration of the af- 



fected tissues he 



ted 



development of 



stage, and this fungus he called Byssothecium circinans (Lep 

 tosphaeria circinans (Fckl.) Sacc, Trematosphaeria circinam 



(Fckl.) A\ 



It will be noted that Winter regarded this 



t 



