MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



23 



Bacillus Viscosus (Frankland). 

 I Fig. 21, PI. II. i 



Found in meadow soil at tho depth of 30 inches. 



Character. — Very slight growth in an atmosphere of hydrogen. 



Morphology. — Small, straight rods with rounded ends, from three to five times as long as 

 broad. Occurs singly and in pairs. 



Motility. — Actively inutile. 



Flagella situated at the poles. 



Spores not observed. 



Colonies on gelatin plates. — Colonics appear in twelve to fourteen hours as minute whitish 

 dots, barely visible to the naked eye. x 80. They are finely granular, grayish disks, with 

 even margins. At the end of eighteen hours the surface colonies are one-half of a millimeter in 

 diameter, circular and whitish, each lying in a small saucer of liquefaction, x 80. They are 

 made up of masses of fine wavy lines, giving a fringed appearance to the margins which are 

 uneven, though generally circular in shape. Liquefaction is rapid, and at the end of thirty-six 

 hours the surface colonies are <i to 8 mm. in diameter, the liquefied gelatin containing grayish 

 flocculi. The edges .are clear cut and circular, x 80. The flocculi are made up of fine threads 

 in tangled masses. At the edge these lines assume an outward direction, forming a corona 

 of fine spear points, the colonies at this stage resembling those of the subtilis very closely. The 

 deep colonies are one-sixth of a millimeter in diameter, and whitish in color, x 80. The central 

 portion is yellowish brown and granular, and is surrounded by a corona of fine wavy lines, whose 

 length is about equal to the diameter of the central part of the colony. Liquefaction is rapid 

 on the surface, and further observation is impracticable. 



Agar slant. — A thin, smooth, glistening, greenish line is formed along the needle mark at the 

 end of twenty-four hours. This soon spreads over a large part of the surface, aud 

 the agar acquires a green tint. 



Gelatin stab. — Growth occurs down the puncture, and a funnel of liquefaction 

 is formed by the second day, in which whitish flocculi are floating. By the third 

 day the gelatin is liquefied to a depth of 1 cm., measured along the tube wall, and 

 the floor is becoming less funnel shaped. A tenacious layer forms on the surface 

 about the fifth day, and the whitish deposit at the bottom is also tenacious. The 

 liquefaction proceeds nearly to the bottom, and the floor becomes level, after which 

 the action seems to cease. 



Potato. — A smooth, moist layer of yellowish hue forms in twenty-four hours. 

 This soon spreads over the entire surface of the plug iu a thin layer, and becomes a chocolate 

 brown about the tenth day. It is smooth, moist, and shining. 



Bouillon. — Diffuse cloudiness, not very intense, is caused by the third day. The bouillon 

 becomes green at the surface, about the same time, the color extending downward, so that about 

 the tenth day it is green all through. A whitish deposit forms at the bottom. 



Bosolie acid. — A slight film forms on the surface, but no change occurs in the color. 



Litmus milk. — Becomes reddish about the fifth day, but no coagulation can be detected. 

 Later the milk becomes watery, apparently from digestion of the casein, and a white deposit 

 collects at the bottom. 



Sugar gelatin, deep stab. — Growth occurs deep along the puncture, with rapid liquefaction, 

 and a layer forms on the surface. No gas is produced. 



Indol. — Reaction negative. An odor like skatol is produced by boiling with sulphuric acid 

 and sodium nitrite. 



Relation t<> temperature. — More rapid at 35° to 36° C. 



Note. — This bacillus was first described by Grace and Percy Frankland in the Zeitschrift fur 

 Hygiene, Vol. VI, 18S'J. 



K^y 



G< 1st;, I,. 



