22 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Litmus milk. — Becomes more blue by the third day. After a week is a pure blue. There is 

 no coagulation or any change apparent in the inilk itself. A yellowish deposit forms at the 

 bottom of the tube. 



Sugar gelatin, dee}) stab. — Very scanty growth, aud confined to the surface mainly. No gas is 

 produced. 



Indol. — Reaction negative. 



Relation to temperature. — Almost no growth at 35° to 36° C. 



Bacillus Striatus Vi^idis. 



(Figs. Wand 20, PI. II.) 



Found at a depth of 18 inches in made soil a number of years old. 



Character. — No growtli at all in an atmosphere of hydrogen. 



Morphology. — Straight, rather slender rods, of variable length, with rounded ends. Each 

 rod is marked by transverse bands which do not take the stain, giving it a striated appearance, 

 not unlike the bacillus Diphtheria: Occurs singly for the most part, though pairs are seen also. 



Spores. — Formation of spores is doubtful. 



Motility. — Actively motile. Occasionally one or more rods will dart across the field with a 

 rapidity which makes it hard to follow them. 



Flagella are situated at the poles. 



Colonies on gelatin plates. — Colonies appear at the end of thirty hours as minute bluish white, 

 translucent dots, about one-sixth of a millimeter in diameter. Deep colonies are punctiform. 

 X SO. Deep are yellowish, finely granular, with circular even edges. Those on the surface have 

 a yellow hue, and three distinct zones can be made out, the color growing paler from the center 

 outward. Growth is slow, and at the end of five days the surface colonies are only 1 mm. in 

 diameter, the deep remaining whitish dots, x 80. Deep appear as dense brown disks with even 

 edges. The surface colonies still show the zones. Just outside of the zone surrounding the 

 nucleus have appeared brownish masses, with clearly defined edges, heaped irregularly on each 

 other, resembling amorphous crystals. The nucleus is usually eccentric. In some colonies these 

 amorphous granules are almost all grouped at one side of the colony, but usually they form a more 

 or less regular circle. (See drawing.) After a few days the colonies become grayish and lose 

 their even margin, a fringe of fine wavy lines having formed. The granules have become more 

 numerous and are more regularly disposed. 



Agar slant. — By the second day a smooth, shining band, with irregular margins has formed, 

 which spreads near the bottom in a very thin almost invisible layer, which has leafy margins. 

 The agar acquires a faint green tint by the third day, which later becomes a yellowish green. 

 The growth soon covers much of the surface of the agar, but is never very thick, aud becomes 

 somewhat shiny. 



Gelatin stab. — Growth is quite slow, aud confined mainly to the surface, where a whitish 

 button, some 2 mm. in diameter, is formed by the end of a week, and later becomes double that size. 

 It has even, elevated margins and is white. There is no liquefaction of the gelatin. 



Potato. — By the second day there is an abundant growth, spreading widely over the plug where 

 it is moist. It becomes a chocolate brown after two weeks, and is moist and shining. 



Bouillon. — Diffusely cloudy at the end of twenty-four hours. Becomes a faint green at the 

 end of a week and the growth settles to the bottom as a white mass. 



Rosolic acid. — -No change in color is produced. 



LiUn us mill,-. — No change is seen until about the tenth day, when it becomes more blue, without 

 any coagulation. After five weeks, the color has been entirely discharged. 



Sugar gelatin, deep stab. — Growth very scanty and mostly on the surface, where a button forms. 

 There is no liquefaction and no production of gas. 



Indol. — Reaction negative. 



Relation to temperature. — Grows well at both room temperature and at 35° to 36° C. 



