56 BACTERIOLOGY 



SYNOPSIS OF THE GENUS 

 I. Chains on all culture media without a thick gelatinous envelope, or at most 

 only a thin capsule. 



A . Non-chromogenic ; no pigment on gelatin or agar. 



1 . Do not grow at room temperatures, or at best but poorly. 



Class I, p. 56. 



2. Grow at room temperatures, and in nutrient gelatine. 



a. Gelatin liquefied. Class II, p. 58. 



b. Gelatin not liquefied. Class III, p. 62. 



B. Chromogenic ; produce a pigment on gelatin or agar. Class IV, p. 68. 

 II. Chains at least when grown in saccharine media surrounded by a gelati- 

 nous envelope. See Nos. 35, 36. 



CLASS I. NON-CHROMOGENIC. DO NOT GROW AT ROOM TEMPERA- 

 TURES, OR AT BEST BUT POORLY 

 I. On the surface of agar a scarcely discernible growth. 



1. Str. giganteus Lustgarten. 



2. Str. enteritis Hirsh. 



II. On the surface of agar a visible growth. 



A. Stain by Gram's method. 



3. Str. capsulatus Binaghi. 



4. Str. Cappelletti. 



B. Decolorized by Gram's method. 



5. Str. Kirchneri. 



1. Str. giganteus Lustgarten 



Str. giganteus-urethrce Lustgarten. 

 Vierteljahresber. f. Derihatol. u. Syph., 1887, 918. 



Morphology. Round, 0.8-1.0, in chains, often of many hundreds of elements, 

 in thick tangled masses. 



Agar colonies. Thin, flat, conglobate ; easily overlooked, iridescent by trans- 

 mitted light. 



Agar slant. Growth mostly in the water of condensation. 



Habitat. In the normal human urethra. 



2. Str. enteritis Hirsh 



Centralblatt f. Bakteriologie, XXII, 1897,369. 

 Morphology. Similar to Str. involutus Kurth. 



Agar colonies. Macroscopically no growth. Microscopically the colonies 

 are small, brown, and coarsely granular. 



