438 MEMOIRS OF THE NATIONAL ACADEiNJY OF SCIENCES. 



IJtiiuis nillh: — Seems flist to beeoiiic a much deeper liliie witli a stroug alkaline reaction. 

 Later it is decolorized, and finally becomes pink, with an acid reaction. Tliere is no coagulation, 

 tbongh the liiiuid may become viscid after some months. 



SH(j<if (lehdin in deep stub. — Fair growth; no gas jjroduction. 



Sosoiic acid. — Decolorized; reaction is alkaline. 



Iiidol prod)(cfion. — Faint reaction; probably does not i)rodace nitrites. 



Relation to temperature. — Grows better at the temperature of the room than at 'i^J^ to .'iC^ C. 



Bacillus fluorescens convexus. 



Isolated from the water of the Schuylkill Eiver. A medium-sized, short, thick, motile 

 laacillus, with rounded ends. It has a polar tiagellum. No spore formation observed. 



Colonics in gelatin. — About the third day the surface colonies are round, convex, smooth, 

 shining, pale greenish, semitranslucent disks, perhaps 2 mm. or 3 mm. in diameter. Under a low 

 jiower they are gre'enish and rather dense, becoming faintly granular and thin toward their 

 margins, which arc smooth, rounded, and sharply defined. The deep colonies under the low power 

 are roundetl and have sharp contours. They are finely granular at the center and show a slight 

 greenish tint. In a short time the gelatin acquires a blue-green fluorescence. 



Gelatin .stab. — Rather narrow, elevated, shining, pale green, thick, smooth-surfaced, viscid- 

 looking growth with sharp contours; the gelatin becomes blue green fluorescent. 



Acid gelatin. — Grows well ; no fluorescence iu the gelatin. 



Agar .slant. — Semitranslucent, moist, viscid-looking, pale greenish, shining stripe, with 

 irregular margins; the agar acquires a green color. 



Bonillon. — Densely clouded and greenish in color; stringy flocculi collect near the surface and 

 there is a whitish sediment. 



Potato. — Pale brown, viscid-looking, irregular, rather widely spreading growth. 



Litmns mill,. — No coagulation and blue color deepened; reaction is alkaline; in milk not 

 colored with litmus no color is produced. 



Sngar gelatin in deep stab. — Only faint develoi^ment; no gas production. 



Eosolic avid. — Color is somewhat deepened. 



Indol production. — Negative or doubtful. 



Relation, to temperature. — Little or no growth at 35° to 36° G. 



Bacillus rugosus. 



Isolated Irom the water of the Schuylkill River. Rare. A medium-sized, motile bacillus, 

 with rounded ends, occurring singly, in pairs, and sometimes iu chains and threads. It has one 

 to four flagella situated at the ends; no spore formation observed. 



Colonies in gelatin. — On the third day the surface colonies are semitranslucent, grayish, 

 slightly elevated, shining expansions with irregular, sharply defined outlines, and, if few iu 

 number, may have a diameter of 3 mm. to 4 mm. Under a low power they are somewhat dense 

 and finely granular and have a "cracked" appearance. Toward the center they have a yellowish 

 brown tint. The margin is very irregular and sinuous, but sharply defined. In a few days they 

 may have attained a diameter of (i mm. to 8 mm., if not numerous, and they are then thin, semi- 

 translucent, greenisli gray expansions, with numerous delicate, somewhat radiating wrinkles 

 throughout the central portions of the colonies. These wrinkles do not extend to the margin of 

 the colony, but there is a smooth border zone all around the periphery. Under a low i)Ower the 

 colony is rather refracting and granular and brownish in tint. The "wrinkles" in the central 

 l»ortion of the colony give the impressiou of a network of crossing beams or of a mass of coiled 

 intestines. In other cases, again, the api)earance may be that of a mosaic. This central portion 

 fades out into a smooth border zone, brownish iu color, which in turn is surrounded by a thinner 

 and colorless, wavy ontlined zone. Deep colonies are rt)un(lcd, brownish m color, and sharply 

 defined. 



(ielatin slant. — A grayish green, rather dense stripe, not widely s|)readiug, showing more or 

 less numerous delicate wrinkles, which form a network. The margin is wavy and sharply dehned 



