182 IMPORTANT VARIETIES OF FISSION- FUNGI. 



ment is developed most abundantly upon agar and po- 

 tato. 



Gelatin plate, (a) Natural size: Small, irregularly 

 roundish colonies of yellowish- white to yellow color. After 

 six days, 1J mm. in diameter. Old colonies are not much 

 larger. The colonies usually sink slowly into the medium 

 and become surrounded by a flat, plate-like zone of 

 liquefaction (8, vii). 



(6) Magnified seventy times. Superficial colonies : Round- 

 ish, faintly yellow to brown, with delicate, transparent 

 peripheral zone. Structure somewhat coarsely granular, 

 toward the periphery a little more finely granular (8, vm). 

 Deep colonies : Roundish to whetstone-shaped, dark yellow 

 to brown, structure finely granular, border almost smooth. 



Gelatin Stab. Liquefaction along the line of punc- 

 ture after two to three days. The zone of liquefaction 

 is conical to bag-shaped, and later cylindric. The con- 

 tents of the cavity are grayish-white, cloudy in appear- 

 ance, and at the bottom a whitish to orange-yellow pig- 

 ment is deposited in little clumps. The intensity of the 

 liquefaction varies widely. 



Agar Plate. (a) Natural size: The superficial colonies 

 are round or roundish, orange-yellow, faintly shining, 

 evenly elevated, and as much as 4 mm. in diameter. 

 Deep : Roundish to whetstone-shaped, equally or more 

 deeply colored and never so large as the superficial (8, v). 



(6) Magnified sixty times. Superficial colonies : Round, 

 almost or entirely even border, with transparent, delicately 

 punctated peripheral zone, orange-yellow, toward the 

 center shaded to homogeneous gray, sometimes with a 

 more darkly colored ring near the periphery. Deep : 

 Colonies partly roundish, partly whetstone-shaped, dark 

 grayish-yellow, opaque, at periphery often somewhat more 

 coarsely granular. Often there are found in agar, broad, 

 pale yellowish, round, transparent colonies with the gran- 

 ulation more marked (8, vi). 



Agar Stab. Stab : Insignificant growth, at first thread- 

 like, later slightly granular. Surface growth : Roundish, 

 evenly elevated, with smooth, somewhat wavy border, 

 faintly shining, orange-yellow (8, in). 



Agar Streak. Corresponds to growth in the stab. 



