MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 4:53 



A{i((r sidiif. — A inilk-wliite shilling stripe ^vitll irregular margins, sharply defined. 



BoniUon. — Clouded. Some lioi'cult near surface and a whitisli llaky sediment. Reaction is 

 alkaline. 



I'otato. — Scanty growth of minute, discrete, and confluent whitisli colonies. 



Ijitmiis miUc. — After about two weeks the milk is viscid, pink above, decolorized below. Later 

 there is a white or pink friable clot and cloiuly serum. Reaction acid. 



Sugar gelatin in deep stab. — No growth. 



Rosolic arid. — Little or no change in color. Growth is not vigorous. 



Indn] production. — Doubtful reaction. The addition of nitrite is necessary. 



Relation to temjperature. — Grows at the temperature of the room and at 3.")0 to .3fP ( ". 



Cladothrix dichotoma (Cobn.). 



Isolated from the Schuylkill water. Long, slender, wavy, branching threads, which show 

 segmentation when stained. Spherical, deeply staining enlargements have been seen in the 

 continuity of the filaments. They are two or three times the width of the filament in their 

 diameters. 



Colonies in gelatin. — On the third day the colonies appear as spherical brownish gray bodies, 

 about 1 mm. in diameter. The gelatin for some distance around each has a rich, dark brown color. 



Under a low power the colony appears as a dark, spherical mass made up of fibrils radiating 

 in all directions from a dark center. Later, as the colony increases in size, evidences of a very 

 slow liquefaction appear, and the brown color in the gelatin spreads farther. The colonies are 

 very dense and hard, and can be broken up only with difficulty. 



Gelatin stab. — First a few discrete, brownish gray, spherical colonies near the surface. These 

 increase in size, coalesce, and form an excavation in the gelatin, with some li(iuefaction, while the 

 superficial layers of the medium acquire a rich brown color. There is some growth along the line 

 of inoculation of discrete, hazy, grayish colonics, growing smaller toward the bottom. The growth 

 in the excavation consists of irregular, du-ty grayish clumps. 



Acid gelatin. — Grows in acid gelatin producing an alkaline reaction. The growth is probably 

 slower. 



Agar slant. — Discrete and confluent round colonies, somewhat elevated and shining, and of a 

 brownish white color, and rather dense. The agar acrpiires a brown smoky color. Later the 

 colonies become larger and disk like, and may present some wrinkling or crimping, while their 

 color is a dirty brown. The growth is very tough and firmly adherent to the medium. 



Bouillon. — The organism grows at the bottom in the form of spherical, hazy masses, which 

 float upward when the tube is shaken. The medium is clear and ac(iuires a deep brown color. 



Potato. — Discrete and confluent, elevated, hemispherical, grayish colored colonies, which may 

 ■be 2 mm. to 3 mm. in diameter. The potato acquires a deep black-brown color. 



Litmus milk. — Viscid coagulation and subsequent dissolving of the casein. Tlie Ii(juid 

 acquires a brown color, and a dense, dirty grayish membrane forms on the surface and adheres to 

 the tube wall. The reaction is alkaline. 



Sugar agar in dee}) stab. — Little or no growth. 



Relation to temperature. — Grows at the temperature of the room and at 3.")^ to 3(P C. 



Remarks. — This cladothrix has been frequently observed in the course of this work. It is 

 undoubtedly identical with the cladothrix dichotoma of Colin, as described by Mac6 (Comptes 

 Eeudus, T. C VI, ISSS. p. IG'2'2). who states that it is a common water organism. 



Cladothrix rufula. 



I.solated from the water of the Sclinylkill River. Rare. Long, slender, wavy, branching 

 threads, which in stained jireiiarations are seen to be composed of ratlier long, sometimes 

 undulating segments, separated l)y a clear interval. 



In a mature culture, siiherical, deejily staining bodies, of a diameter two or tiiree times tiie 

 width of the threail which bears them, may be seen. They are in the continuity of the filament 

 or often at its end. 



S. Mis. r.O 28 



