440 MEMOIRS OF TUE NATIONAL ACADEMY OF SCIENCES. 



Colonies in gelatin. — On the tbird or fourth day the surface colonies are grayish, translucent,, 

 rather irregular outlined expansions, somewhat elevated aud shining, and about 2 mm. in diameter. 

 Under a low power they are tiuely granular, translucent, somewhat refracting, with sharply 

 defined, irregular, wavy outlines; a minute, central nucleus may be seen in them, and they may 

 have a slight brownish tint toward their centers. The deep colonies are rounded and shari)ly 

 defined in outline; they are finely granular, not dense, and have a brownish center, surrounded by 

 a dark ring in some cases. 



Gelatin slant. — Narrow, semitrausluceut stripe, with slightly irregular, sliarplj' defined margins ;: 

 the growth is somewhat creamy gray in color, and has a yellowish tint by transmitted light. 



Acid gelatin. — Good growth; but perhaps not so vigorous as in the ordinary gelatin. 



Agar slant. — Thin, translucent, not widely spreading layer, with sharply defined, slightly 

 irregular margins. 



Bouillon. — Clouded; a thin grayish follicle forms on the surface, and there is some sediment. 



Potato. — Brown, viscid, shining, semitranslucent, not very widely spreading layer, somewhat 

 elevated and growing somewhat irregularly. 



Litmus mill;. — The blue color is much deepened: there is no coagulation, and the reaction 

 is alkaline. 



Sugar gelatin in deep stab. — Little or no growth. 



Rosolic acid. — Little or no change in color. 



Indol production. — Negative. 



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



Bacillus siiiuosus. 



I.solated from the water of the Schuylkill liiver. At one time not uncommon. A medium- 

 sized, short, motile bacillus, with rounded ends, occurring often in pairs and sometimes in longer 

 forms. It has a polar tlagellum; some individuals probably have two to four tlagella; no spore 

 formation observed. 



Colonies in gelatin. — On the second or third day the surface colonies are very thin, delicate, 

 grayish, translucent, aud opalescent expansions, with very irregular, sinuous outlines, and of a 

 diameter of several millimeters, if the colonies are not too numerous. Under a low power tliey 

 are thin, translucent, vei'y irregular and sinuous in outline, and sh(jw various waving and irregular 

 lines, especially near the margins, which suggest the appearance of wood graining. Sometimes 

 they are brownish toward their centers. If the colonies are widely separated they may attain a 

 diameter of G mm. or more, and in such a large colony delicate radiating foldings have been 

 observed running from a faint whitish nucleus toward the periphery. The outline in the large 

 colonies is extremely irregular and sinuous, and they remain thin and translucent, while under the 

 low power they are seen to have lost the "wood graining"' appearance, and are finely granular. 

 The deep colonies under a low power are finely granular and brownish, with rounded or slightly 

 irregular, sharply defined outlines. 



Gelatin slant. — Grayish white, smooth, shining, semitranslucent stripe, with sharply defined, 

 irregular margins; does not spread widelj. 



Acid gelatin. — Grows well. 



.-liy«r slant. — Narrow, grayish white, thin, shining, semitranslucent stripe, with shghtly 

 scalloped margins. 



Bouill(fn. — Clouded and has a whitish, stringy sediment; no pellicle on surface. 



Potato. — Dirty brown-gray, moist, not thick, rather rough appearing growth, which spreads 

 rather widely. 



Litmus mill-. — Pink, white at bottom; no coagulation after six weeks at the temiierature of 

 the room ; reaction is acid. 



Sugar gelatin in deep stab. — A thick cord of conHuent whitish colonies forms along the line 

 of inoculation, and there is an abundant production of gas. 



Rosolic acid. — Color is deepened. 



Indol production. — A faint reaction; the addition ot nitrite solution is necessary. 



Relation to temperature. — Grows well at the temperature of the room and at 35° to 30"^ C. 



