354 IMPORTANT VARIETIES OF FISSION-FUNGI. 



the form of a semicircle. By the adhering together of 



two ribriones there occur such forms as these: S and >. 



Under unfavorable conditions of growth (lack of oxygen, 

 lack of albumin, etc. ) the vibriones grow into true screw 

 forms, which often cannot be recognized as composed of 

 separate vibriones. According to Cramer, under espe- 

 cially favorable conditions (soda bouillon in a thin layer) 

 there occur especially short oval or cocci-like formations. 

 In old cultures there are manifold involution forms (51, 



IV). 



Motility. — Very distinct, rapid, turning motion, de- 

 pendent upon one, rarely two, long, terminal flagella 

 Avhich are somewhat spiral in form (61, ii). 



Staining Properties.^Stains with the ordinary anilin 

 dyes, but not especially easily; not by Gram's method. 

 Usually carbol-fuchsin diluted ten times is employed for 

 staining, it being allowed to act for a few minutes when 

 warm. 



Relation to Oxygen. — Aerobically, and much more 

 slowly anaerobically, it forms powerful toxins. 



Intensity of Growth. — Optimum at 37°, but also 

 very well at 22°. The lower limit of growth has been 

 found to be 10°-12°, sometimes 8°. 



Gelatin Plate. — At first small, yellowish-white to yel- 

 low, roundish colonies, which as early as twenty-four to 

 thirty-six hours sink into the gelatin in holes, and later in 

 saucer-shaped areas of liquefaction. 



(a) Natural size : The rapidly enlarging zone of lique- 

 faction at first remains clear (48, vi); later it becomes 

 cloudy, and usually gray, from the colonies disintegrating 

 more and more (48, vm). In many cases after a longer 

 time there are present in the Hquefied zone concentric 

 rings (48, ix), which increase from day to day (48, vii). 



(6) Magnified sixty times: After sixteen to twenty-four 

 hours the colonies are visible as minute, pale-yellowish, 

 roundish, coarsely granular disks with more or less of a 

 crumbly character at the border (49, i). Often at this 

 stage a beautiful, intensely red reflex appears at the per- 

 iphery of the colonies, the older the individual colonies 

 become, the more the granular character increases, and a 



