132 PROTECTION OF PLANTS — 1923-24 



The Quebec organism grew well in all the flasks with marked similarity in 

 type. For the first week the culture gave a soft, white submerged mycelial 

 growth and on the ninth day a white surface mat had formed which by the 

 eleventh day was showing a pink coloration on the surface of the mat. This 

 pink. coloration, on close examination, was found to be due to large numbers 

 of circular pink bodies, hard in texture, which when crushed under a cover 

 glass discharged large numbers of what appeared to be oil globules. By the 

 sixteenth day this pink coloration had changed to dark brown and in a number 

 of flasks to a distinct black. On examination under the microscope this black 

 growth was found to consist of large masses of coalescing sclerotia. No spores 

 were found in any of the cultures examined. The surface layer at the end of 

 the sixteenth day varied in thickness from l-16"-l-8". 



Vermicularia varians, C. tahificum, C. atramentarium, and C. atrovirens 

 showed the same growth exactly as that of the Quebec organism. 



The Saltation differed in type of growth from the others in some respects. 

 On the third day small particles of white, downy mycelial growth were visible 

 throughout the liquid. By the twelfth day white submerged growth had become 

 denser while, in some flasks there appeared white horn-like structures protru- 

 ding from the surface of the liquid. On examination these proved to be dense 

 rope-like masses of mycelium. No pink coloration was noted and no surface 

 mat of mycelium was formed. At the end of the growth period nothing but 

 a submerged mass of white mycelial growth could be seen. 



The following diagrams represent the arrangement of the triangular system 

 The area within the dotted lines in each case represents the twelve cultures 

 making the best growth: — 



