MEMOIKS OV THE NATIONAL ACADEMY OF SCIENCES. 



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TJtiiiKs tiiill,-. — 1 >('i'()li(rizc(l and coaiiiilated after a week or two: tlio clot is jelly like, and the 

 seruin is cloudy and of a yellow color; tlierc is a yellow riiiu' on tiie tube wall al)o\c the level of 

 the liiitiiil; the reacti(*n is neutral. 



)>!ii(iitr (jeUithi ill deep ntub. — No f;rowtli. 



h'osolic iieid. — fjittle or no growth. 



Ituliil iiriuhu-tiiiii. — Netiative. 



BcUitiiiii to 1ciii]>cr<it>irc. — !)((es not grow at .'55'^ tc .Sfio C. 



Bacillus decidiosus. 



Isolated from the water of the Schuylkill Kiver. Has been seen in the Delawaie water. A 

 sniall, short, iwnmotile bacillus with rounded ends, occurring often in pairs, and showing a 

 tendency to gather in "clumps;" no spore fornuition ol)ser^•cd. 



Colonics ill geJatin. — On the second or third day the colonies appear as small, yellow-brown, 

 irregular clumps, about 1 mm. in diameter, usually lying in depre-ssious containing clear li(|uetied 

 gelatin ; sometimes a brown spot may be seen at the center. Under a low magnifying jiower they 

 are rather dense, granular, and of a brown-yellow <'olor, sometimes with a dark br()wn area at the 

 center. The outline is irregular and broken, while around some a refractive ring of li(pieficd 

 gelatin may be observed. In a day or so the colonics have increased somewhat in 

 size, and may api)ear to be partially split uj) into smaller, irregular, j-ellowisli clumps, 

 while the area of liquefaction around each is greater. (See PI. I, ftgs. .^ and 6.) 



Gelatin stab. — Liquefaction extending down the line of inoculation in the form of 

 a funnel constricted at the top and inclosing an air bubble (tig. 2). The licpntied 

 gelatin contains yellowish floccnli in susjiension, and is clouded. On the surface a 

 j'ellow clump and at the bottom a yellowish precipitate; the reaction is alkaline. 



Acid (jclatiii. — Growth is slower and development along the line of inoculation is 

 fainr. 



Aijar slant. — Shining brown-yellow, scmitranslucent, not widely spreading growth, 

 comxwsed of discrete and confluent rounded colonies. 



Bouillon. — Clouded; in older cultures a brown greenish color may be observed, 

 and the li(iuid may be clear, with a stringy sediment at the bottom. 



Potato. — I?rown-yellow, moist, elevated, rough, irregular gr(jwth, somewhat viscid 

 looking. 



Litmus iiiilli. — Viscid clot with cloudy, yellowish serum above. A brown-jellow 

 scum may form on the surface after some weeks; ou tube wall a bluish ring above a yellow ring; 

 the casein seems to be gradually dissolved; the reaction is alkaline or neutral. 



Siujar gelatin in deep stab. — Some growth and liquefaction; no gas ju'oduction. 



Rosiilic acid. — Effect is uncertain. 



Jndol reaction. — Faint or doubtful reaction; does not produce nitrites. 



Relation to temperature. — lioes not grow at 35° to 36° C. 



Fir,. 



Bacillus amiulatus. 



Isolated from the Avater of the Schuylkill Kiver. A rather small motile bacillus, with rounded 

 ends, occurring singly, in pairs, and longer forms. It Ims several Hagella. ai)parently situated 

 at one or both ends. 



Colonies in gelatin. — About the third or fourth day the colonies have formed round, saucer- 

 sbaped li(iuefactions, 2 mm. or 3 mm. in diameter; there is a yellowish mass at the center, and 

 this is surrounded by a cloudy zone of li(pielied gelatin. lender the low magnitying power a 

 thick, opa(pie yellowish clunq) is seen at the center, around this dark granular material, and at 

 the margin of the liquefaction sometimes an indistinct fringe of short hair-like processes, or the 

 outline maybe ill defined : motion of a circulating character maybe observed in the liquefied 

 area. The deeper colonics, under the low i)ower, are oval or irregularly round, brownish, finely 

 granular, and sharply detiued. If the colonies are few in number the liquefactions may attaiu a 



