460 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Siiuar (jcJatin in deep sluh. — Points of liquefaction containing' pinkish tlocculi along the line of 

 inocnhition; later liquefaction all along tlie line irregularly, and here and there pinkish clumps; 

 in i)]aces groups of delicate lateral furry outgrowths; no gas is produced. 



RosoUc acid. — Color deepened. 



Indol producfioit. — Negative. 



Relation to temperature. — Does not grow at 35° to 3(P C. 



Bacillus flexuosus. 



Isolated from the water of the Schuylkill Ei ver. Not a common species. It has been observed 

 in the water of the Delaware also. A medium-sized, short, thick bacillus with rounded ends, 

 occurring often in pairs, and may grow into long forms, threads, and chains. 

 The motility is doubtful; usually not motile; uo spore formation observed. 

 Colonies in gelatin — About the second day the surface colonies appear as whitish, somewhat 

 irregularly outlined clumps in a depression containing clear, liquefied gelatin. Under a low power 

 they give the impression of being made up of looped and twisted granular strands or cords closely 

 packed together. (I'l. II, fig. 10.) At their centers they are dark and opaque with sometimes a 

 greenish glimmer, while at their i^eripheries the arraugement of the strands is some- 

 what looser and they are less dense. 



The outlines, being determined by the marginal strands, are irregular, but sharply 

 defined. 



In some colonies two or three of the component strands may become loosened 

 from the rest and may appear as long, slender threads, finely undulating in places and 

 sometimes looped or twisted, floating in the surrounding liquefied gelatin. 



The deep colonies are rounded or slightly irregularly oval, brownish, and finely 

 graTiular, with sharp contours. 



Gelatin stab. — Liquefaction in deep saucer form extending to the tube wall and 

 downward, the liquefied gelatin coming to be separated from the nonliquefied by a 

 horizontal plane on which a whitish sediment is seen (fig. 24). The liquefied gelatin 

 is clouded and there is a thin i)ellicle on the surface. 

 There is faint growth in line of inoculation. 

 The reaction of the liquefied gelatin is alkaline. 

 j,jg ,j Aeid gelatin. — Grows less vigorously; the reaction is nearly neutral. 



Agar slant. — Narrow semitranslucent grayish stripe with slightly scalloped, 

 sharply defined margins; the agar acquires slight greenish tint. 



Bouillon. — Clouded and contains flocculi; it acquires a slight greenish tint; at the bottom 

 there is a stringy sedimeut. 



Potato. — Brown, viscid-looking, moist, uneven growth, not widely spreading. 

 Litmus mill;. — Coagulated; pink in upper layers and white below; some cloudy serum after 

 a time; pink ring on tube wall; the reaction is acid. 

 Sugar gelatin in deep stab. — Very faint development. 

 Bosolic acid. — Effect is uncertain. 



Indol I'roduction.—Donhtfu] or ftiint reaction; the addition of nitrite is necessary. 

 Eelution to teniperature. — Very slight development, if any, at 35° to 36° C. 



Bacillus coadunatus. 



Isolated from the water of the Schuylkill River. A medium-sized, generally short, motile 

 bacillus, with rounded ends, occurring singly, in pairs, and in threads and chains; it has a polar 

 flagelluni; no spore formation observed. 



Colonies in gelatin. — About the third or fourth day the colonies are brownish white, rouud, 

 rather dense and less than 1 mm. in diameter, some of them being sunken in the gelatin with 

 evidences of liquefaction. 



Under a low power they are highly granular, dark brownish, sometimes browu-green in tint 

 at the center, with rough, ill-deflned frayed margins, in some cases showing irregular, short, hair- 

 like projections. (PI. I, fig. 13.) Typical and characteristic colonies are surrounded by a narrow, 



