MEMOIUS OF THE NATIONAL ACADEMY OF SCIENCES. 435 



Eosolic acid. — Giowtli not vi,i;()ious. Probably somewbat decolorized. 



IndnJ prodiirtiiiii. — Reaction dinihtfnl. TIk' addition of nitrite is necessary, (irowtli is not 

 vigorous. 



RcltitioH lit iciiiinrdtiirc. — Does not gi'ow at 35° to 30° (J. 



Bacillus ovalis. 



Isolated from tlie water of tlie Scbuylkill liiver. Rare. A inediumsizetl, siiort, rounded, 

 iioniiiotilc bacillns, oeeurrinj:' in pairs and oecasionally in lonu' forms. 



^o spore tbrnnitiou observed. 



Colonics ill (lelaiiii. — <Vfter li\e or six days the surface colonies are shining-, rounded, yellowish, 

 elevated and semitranshuent, with sharjily defined contours, and are of a diameter of about 

 1 mm. Under a low power they are higlily refracting and of a warm yellow tint. The deei> 

 colonies, when magnifled, are rather opaque and granular, with siiarply defined, rounded outlines, 

 and have'a brownisli color. 



After a time the surface (colonies maj' attain a diameter of about li mm. or so, and become 

 more elevated and of a darker yellow or brown-yellow color, while the gelatin acquires a slight 

 brown tint. 



They are shining aud smooth on the surface, are slightly translucent, and have a sharply 

 defined, rouiuled outline. 



(Iclutiii slant. — An elevated, brownish, yellow, dense, somewhat viscid looking growth, not 

 spreading widely, but confined to the line of inoculation. The surface is shining and is sometimes 

 smooth, though usually uneven and somewhat rugged, while the margin is slightly irregular 

 but sharply defined. The gelatin acquires a brown tint after a time. When the growth is younjj 

 it is of a pale yellow color. 



Acid fjrlatiii. — Gro\\s well. 



Agar nUiiit. — Pale, yellow, irregular, rather dense, shining growth, not spreading widely. 



Bouillon. — Whitish, llocculent sediment. The liquid is clear. There may be a ring of minute 

 yellowish fiocculi on the wall of the tube at the level of the liquid. 



Potato. — Viscid, dirty brown-yellow, moist layer, spreading rather widely. 



Litmus milk. — Decolorized, not definitely coagulated. A yellow scum adheres to the tube wall,, 

 and the milk has an acid reaction. A yellowish, viscid material has been noted on the surface. 



Siif/ar aijat in deep stab. — Only slight development; no gas production. 



Bosolic acid. — Does not grow vigorously; etfect uncertain. 



Indol production. — Faint reaction; growth not vigorous; does not form nitrites. 



Relation to temperature. — Does not grow at 35° to 36° 0. 



Bacillus lacunatus. 



Isolated from the water of the Schuylkill Eiver. Rare. A small, short, rounded, nonmotile 

 iiaciilus; occurring often in pairs and sometimes in snuill chunps. The length is somewhat 

 variable. No spore formation observed. 



Colonies in gelatin. — After about twenty-foirr hours the surface colouies are excessively thin, 

 transparent expansions, slightly grayi.sh toward the center, and have very irregular outlines. 

 They may be -' mm. or 3 mm. in diameter. (See PI. II, fig. 11.) 



ruder a low power they are very transparent and thin, granular at their centers, and very 

 irregular aud deeply cleft in outline. 



In some cases small, irregular open spaces or lacuna- may be seen where the growth is 

 inconq)lete, and here and there, near the margins, faint, wavy, irregular lines, which recall the 

 appearance of wood graining. The deep colonies are rounded, siiarply defined in outline, faintly 

 granular, and grayish brown in tuit. By the second or third day tin' colonics have increased 

 somewhat in size aud may have a diameter of 4 mm. to 5 mm. They remain thin and translucent, 

 but develop a yellow haziness about their centers. 



Gelatin slant.— A thin, translucent, more or less wide stripe with very irregular, wavy, or 

 dentated margins. The color is grayish at first, later becoming more or less yellow, usually along, 

 the central portion. 



