448 ACTINOMYCETES. 



Spontaneous motion is lacking. 



Staining Properties. — Stains with ordinary anilin 

 dyes, and by A^'eigert's modification of Gram's method, in 

 which anihn is used instead of alcohol after the iodin. 



According to Nocard, it does not stain well -with the common anilin 

 dyes. According to Berestnew, it stains by Ziehl's method (Z. H. 

 XXIX, 94) ; but according to Nocard, it does not. We could not 

 repeat the tests, as our culture proved to be dead. 



Requirements as Regards Temperature and Com- 

 position of Nutrient Media. — Not particular as to 

 nutrient medium; grows at room temperature, and espe- 

 cially at 37°. 



Gelatin Plate. — (o) Natural size : Scanty growth. 

 After ten days there are only minute, round, transparent, 

 shining colonies (66, v). 



(6) Magnified fifty times : The superficial and deep col- 

 onies appear as smooth-edged, shining, gray to grayish- 

 green masses in which no finer structure is distinguishable 

 (60, VI). 



Gelatin Stab. — Scanty; after twelve days the surface 

 growth is whitish and granular; that in the stab crumbly 

 (66, II). 



Agar Plate. — (a) Natural size: The superficial colonies 

 reach a size of 1 to 2 mm. , are yellowish-white, irregular 

 in form, and shining. The deep colonies remain tiny 

 (66, VII). 



(6) Enlarged fifty times: The surface colonies are similar 

 to those on gelatin plates. The deep colonies are bright 

 yellow, delicate, distinctly filamentous, and curly in struc- 

 ture (66, vni). 



Agar Stab. — About like the gelatin stab. Upon the 

 surface of the agar there forms a whitish, coarsely granular 

 mass, which is very irregular in shape because of fissures. 

 The faintly colored growth shows air mycelium in spots 

 (Nocard). 



Agar Streak. — After eight days there is formed a gray 

 to yellowish-white growth, consisting of transparent col- 

 onies, with a rough, finely fissured surface. The colonies 

 are slightly or not at all connected. The water of conden- 

 sation is clear, with slight grayish- white precipitate. After 



