94 ESSENTIALS OF BACTERIOLOGY 



Origin. In the upper layers of garden or farm grounds and 

 in water. 



Form. Short rods, with rounded ends, about three times 

 as long as they are thick; often in long threads and chains. 



Properties. Large, shining, oval spores; a slight movement; 

 liquefy gelatin. 



Growth. At ordinary temperature, with plentiful supply of 

 air. 



Plate Colonies. Look like roots of an old tree gnarled 

 together, radiating from a common center. Liquid on surface. 



Stab-culture. Soon a growth occurs along the needle-track, 

 and the whole resembles a pine tree turned upside down. The 

 gelatin then becomes liquid, a thin skin floating on top, and 

 small flakes lying at the bottom. 



Stroke-culture. Feathery resemblance is produced. 



Staining. Spores stain readily with the ordinary spore stain. 



Bacterium Zopfii (Kurth) .Origin. Intestines of a fowl. 



Form. Short thick rods forming long threads coiled up, 

 which finally break up into spores, which were once thought to 

 be micrococci. 



Properties. Very motile; does not dissolve or liquefy gela- 

 tin. 



Growth. In thirty hours abundant growth; aerobic; grows 

 best at 20 C. 



Plates. Small white points which form the center of a very 

 fine netting. With high power this netting is found composed 

 of bacilli in coils, like braids of hair. 



Excellent impress or "Klatsch" preparations are obtained 

 from these colonies. 



Staining. Ordinary dyes. 



Bacillus Subtilis (Hay Bacillus) (Ehrenberg) . Origin. 

 Hay infusions; found also in air, water, soil, feces, and putre- 

 fying liquids. Very common, often contaminates cultures. 



Form. Large rods, three times as long as broad; slight 

 roundness of ends; seldom found singly; usually in long threads. 

 Flagella are found on the ends. Spores of oval shape, strongly 

 shining, very resistant. 



