172 IMPORTANT VARIETIES OF FISSION-FUNGI. 



Media. — Grows best at 37°, but also at room temperature, 

 upon all ordinary nutrient media. 



Gelatin Plate. — (a) Natural size. Superficial: Small, 

 irregularly shaped colonies, with even border, whitish, 

 slightly elevated, shining, moist. Deep : Uncharacteristic 

 (7, vii). 



(b) Magnified fifty times. Superficial: Roundish colonies, 

 at first with perfectly even borders, later sinuously broken, 

 not unlike liquefying sarcina colonies. With accurate 

 focusing the form of tetrads is recognizable in the gray, 

 transparent peripheral portion ; toward the center the 

 colony is opaque, shaded gray. Deep : Irregularly formed, 

 smooth border, opaque, delicately to coarsely granular 

 (7, vm). 



Gelatin Stab. — Stab : At first thread-like, later, in upper 

 part very granular, in lower part like a string of pearls, 

 white (7, n). Surface growth : After ten days from 3 mm. 

 to 4 mm. broad, irregularly round, partially lobulated, 

 much elevated in the center, like the head of a nail, moist, 

 pure white or somewhat yellowish, shining (7, in). 



Agar Plate. — The same as upon gelatin, only much 

 more luxuriant, opaque (7, vi). 



Agar Stab. — Stab : Confluent, very rough, pure white. 

 In old cultures there often occur luxuriant outgrowths in 

 clumps (7, v). Surface growth : Irregularly round, sin- 

 uous or wavy. Much elevated, often with terrace-like 

 formation, pure white, with an oily luster, at times with 

 a suggestion of yellow (7, iv). The agar streak corre- 

 sponds. Water of condensation clear, with white precipi- 

 tate (7, i). 



Bouillon Culture. — Clear ; moderate precipitate, upon 

 shaking becoming distributed at first as flocculi and then 

 homogeneously. 



Milk Culture. — After four days firmly coagulated, at 

 other times coagulation is absent. 



Potato Culture. — Limited to the streak of the inocula- 

 tion, sharply outlined from the surroundings, but not 

 elevated. Border of the growth irregular and jagged, 

 pure white, dull, or faintly shining. According to Gaffky, 

 thick, slimy, tenacious (7, x). 



Chemical Activities. — It produces some acid upon 



