318 IMPORTANT VARIETIES OF FISSION-FUNGI. 



united in long strings, and not infrequently the separation 

 into individual rods is indistinct, so that long threads 

 occur (40, v). 



Spores. — When air is admitted, oval spores are readily- 

 formed, which germinate at right angles to the long diam- 

 eter. (Compare p. 27.) 



Motility. — The short forms are very actively motile 

 because of long, abundant, peritrichous flagella. The 

 chains of bacilli still show flagella, even when they are no 

 longer motile (40, vi, ix). 



Staining Properties. — Stain by Gram's method. 



Requirements as to Nutrient Media and Oxygen. 

 — Grows upon the most various nutrient media at room 

 and incubator temperatures, but when oxygen is ex- 

 cluded it grows poorly and without sporulation. Growth 

 is rapid. 



Gelatin Plate. — ^(o) Natural size: In a short time the 

 colonies sink into a saucer-shaped depression. The con- 

 tent of the liquefied zone is grayish-white. At the center 

 lies the whitish, ragged colony (40, in). A later stage is 

 shown in 40, iv. 



(6) Magnified sixty times : At first the colonies are round- 

 ish, even-edged, crumbly, yellowish, sometimes surrounded 

 by a delicate row of hairs (40, ii, i). Later, especially in 

 the case of the superficially located colonies, the periphery 

 becomes wavy, and with advancing liquefaction of the 

 gelatin breaks up into innumerable tangled locks, which 

 surround the colony. The central part is still held firmly 

 together, being granular and yellowish to brownish until 

 after four to five days, when it also becomes completely 

 disintegrated (40, ii, e). 



Gelatin Stab. — The surface growth is whitish-gray, 

 and, after thirty-six hours, sinks into the gelatin in the 

 form of a saucer. The gray liquefied content of the 

 saucer contains whitish bunches in suspension (39, i). 

 The liquefaction progresses in a cylindric form, the con- 

 tents being grayish- white, and cloudy, especially below. 

 Upon the surface is a thick white scum, firmly attached 

 to the wall of the tube (39, ii). 



Agar Plate. — (a) Naiumlsize: Small, irregular, shining, 

 grayish-white colonies (39, viii). 



