20 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Agar slant. — xV whitish, elevated growth, which soon becomes almost pure white and mouldy 

 looking, is formed in the course of three or four days, and takes firm hold on the agar. After some 

 time it splits here and there, and shows a dark-brown underlayer, the edges of the fissured crusts 

 curling back a little. It has a strong smell of rotten wood. At the end of three or four weeks 

 the agar turns slightly darker. 



Gelatin stab. — By the third day there is good growth down the puncture, fine outgrowths 

 having formed for some distance. A white button forms on the surface, and under this slow 

 liquefaction goes on. The depression has at first a punched out look, with perpendicular walls. 

 It finally reaches the tube wall in about eight days, leaving a ring of gelatin attached to the 

 tube at the surface. The liquefied gelatin is almost clear, and the floor has whitish masses on 

 it. There is no-discoloration of the gelatin observed. 



Potato. — At the end of three days a scanty almost colorless growth has formed along the line 

 of inoculation, and the potato is distinctly whiter for a distance of 1.5 mm. along each border. 

 The growth becomes a faint yellow, but is always very scanty and thin. 



Bouillon. — The liquid remains clear, but becomes slightly darker. A mass of whitish ball-like 

 flocculi collects at the bottom, and colonics about 1 mm. iu diameter form aiound the tube at the 

 surface. 



Rosolic acid. — No growth. 



Litmus milk. — Becomes more blue by the third day, and a mass of growth floats on the 

 surface. It slowly acquired a beautiful violet tint by transmitted light, and at the end of four 

 weeks has changed to a cherry color. The casein seems to be dissolved without previous coagu- 

 lation. The reaction is strongly alkaline. 



Sugar gelatin, deep stab. — Growth as iu plain gelatin. No gas production. 



Tndol. — Slight color after standing several hours with both sulphuric acid and sodium nitrite. 



Relation to temperature. — Grows more rapidly at 35° to 30° C. than at room temperature. 



Bacillus Fluorescens Undulatus. 



(Figs. 17 aud 18, PL II.) 



Found at a depth of 14 inches in made soil a number of years old. 



Character. — Requires oxygen for its full development, though there is some growth in an 

 atmosphere of hydrogen. 



Morphology. — Slender, straight rods with rounded ends, from seven to eleven times as long as 

 broad. Forms long chains. 



Spores are small and oval in form. 



Motility. — Actively motile. 



Flagella are situated at the poles. 



Colonies on gelatin plaits.— The colonies appear in about thirty hours as greenish dots. X 80. 

 Deep colonies are dense looking brown or gray disks, darker in the center than at the edges, where 

 masses of fine wavy lines can be made out. The surface colonies look much like drops of moisture 

 at the end of thirty-six hours, and have a greenish hue. x 80. They are gray disks, with a well 

 defined nucleus, eccentrically placed aud somewhat granular looking. Around the nucleus, and 

 apparently coming out of it, is a zone composed of the most exquisitely fine hair lines, wavy 

 and packed closely together. At the end of three days the surface colonics are 1 mm. in diam- 

 eter and do not increase in size, but become more dense and elevated. The surface is convex, 

 white in color, with a greenish, iridescent hue. The deep never become larger than one-fourth of 

 a millimeter, x 80. The deep, after a week, are much the same as described above, but more 

 dense and granular. The edges are well defined and even. Those on the surface have become 

 so dense that the structure can not be made out except near the margins, where fine stria' are 

 seen. The nucleus remains visible. There is no liquefaction of the gelatin, and it acquires a 

 faint green color around the colonies. 



Agar slant. — In twenty four hours a thin, translucent, greenish band 2 mm. long has formed 

 along the line of inoculation. It never becomes thick, and after four or live days has spread to 

 the tube wall in a very thin layer for the lower third. It has dentate margius. The color is 

 imparted to the agar — a faint clear green. 



