MEMOIKS OF THE NATIONAL ACADEMY OE SCIENCES. 



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Fiu. 



the bottom. In the case of the variety b of this baciUus, before mentioned, liquefaction proceeds 

 near the surface in a manner sinnhir to the above, but in addition extends along- the inoculation 

 line (tig. 7). The gelatin along the line of iuoculation lias a hazy ai)peai-an(!e foi- .some 

 distance on each side. The ]i(|uetied gelatin in both varieties lias an alkaline reaction. 

 Acid (jeJatin. — No growth. 



Atjur slant. — Translucent, yellow, iridescent layer, with iil-delined transparent 

 margins. 



HiiniUoii. — Clouded: yellowish sediment at the bottom, while on tlic 

 surface a broken yellowish pellicle forms: the bouillon ac(|uires a yellow 

 tint. 



Piitdto. — A warm, orauge-colored, viscid-looking, thick, shining, widely 

 spreading layer. 



Litiinif! viilk. — Decolorized and .slowly coagulated; yellow tlakes at the 

 surface; the reaction is neutral. 



Su(/((r geldtin in deep stub. — No growth. 

 Rosalie avid. — Decolorized; reaction alkaline. 

 Indol production. — Negative or doubtful. 

 lieUition to temperature. — Does not grow at 35° to 30° C. 

 Remarks. — This organism was first described by the Franklands 

 (Ueber einige typische Mikro-organismen im Wasser und im Bodeu, Zeitschrift fiir 

 \ ^ ^ Hygiene, Bainl VI, pp. 379, 380, ISSO), who found it in the water supplj' of Lomhtn. 

 Tils met with it in the Freiburg water supply (Bakteriologi.sche X'ntersuchung des 

 Freiburger Leitungswassers, Zeitschrift fiir Hygiene, 1890, Baud IX), and Tataroft' 

 includes it in his list of organisms isolate<I from the supply of Dorpat (Die Dorpater Wasserbakte- 

 rien. Inaugural Dissertation, Dorpat, 1891). It has been observed both in the Delaware and 

 Schuylkdl in the course of this work. 



Bacillus exiguus. 



Isolated from the Schuylkill water. Observed but once. A small nonmotile bacillus, with 

 rounded ends, occurring singly, in jiairs, and in small clumps. No spore formation observed. 



Colonics in gelatin. — < )n the third day the surface colonies are round, pinkish, semitransluceut, 

 shining disks, with sharply delined outlines. Under a low magnifying power they are granular 

 and have a pink color, which disappears near the margin, where they are thin and translucent. 

 The outline is smooth, rounded, and shaiply defined. The deep colonies are rounded or oval, 

 dense, greenish at the center, granular at the margins, and have smooth, sharply defined outlines. 

 About the sixtli day liquefaction may have become well marked and the colonies have acquired 

 a salmon-pink color. The litiuefying colony has a less sharply defined outline and is 

 surrounded by a zone of cloudy liquefied gelatin. Under a low power the colony is 

 seen to be denser, reddish in color, and granular, and to liave rough, ragged outline. 

 The liquefied zone is filled with rather course granules of a brownish tint, and gradually 

 fades out into the surrounding gelatin. 



Gelatin stab. — Liquefaction in saucer form extending to tube wall and downward; 

 the bottom of the liquefaction is rounded for some time after the wall of the tube has 

 been reached, but eventually becomes a horizontal plane (fig. 8). There is only slight 

 gTowth in the line of inoculation; the liquefied gelatin is clouded and there is a pinkish 

 yellow sediment; the reaction is slightly alkaline. 



Acid (jelatin. — Growth is slower and there is less liquel'action. 



Agar. — Very thin, moist, translucent growth, of a pale jiinkish tint, not widely 

 spreading, and with irregular margins. 



Bouillon. — Clouded; a v.-hitish viscid sediment. 



Potato. — Widely spreading, moist, shining growth, of a red-j'ellow color. 



Litmus milk. — Coagulated and decolorized; clot is jelly-like and is gradually dissolved; serum 

 is cloudy, and of a red yellow color; there is an orange- yellow ring on wall; the reaction is neutral. 



Sugar gelatin in deep stab. — No growth. 



riG. 8. 



