DESCRIPTION OF SPECIES 



445 



Agar plates and tubes — Small 

 white colonies, granular, and some- 

 times showing lobulation. Thread- 

 like, and later granular needle 

 track. Growth in stab-cultures : a 

 grey irregular surface growth. 



Potato — "Invisible" growth, at 

 times absent, rarely abundant. 



Milk — Is usually firmly coagu- 

 lated in from 4 to 24 hours. 



Glycerine ascites agar — Luxuri- 

 ant colonies ; from periphery of 

 colony coiling chains spread out ; 

 granulation in interior of colony 

 more marked than upon agar. 



Anaerobic or aerobic — Faculta- 

 tive anaerobe. 



Vitality — Considerable, retained 

 several months, especially in dried 

 pus. In cultures, usually only for 

 a few weeks ; but in bouillon to 

 which hydrogen is admitted, the 

 streptococcus will live for months. 



Pathogenesis — Pathogenic for 

 mice and rabbits, and less so for 

 dogs and rats. In man strepto- 

 cocci have been successfully in- 

 oculated, producing erysipelas, 

 suppuration, etc. 



STREPTOCOCCUS SCARLATIN.^ 

 ( Klein and Gordon). STREPTOCOC- 

 CUS CONGLOMERATUS (Kurth). 



Source and habitat — Isolated from the 

 blood, nasal and tonsillar discharge 

 of persons suffering from scarlet 

 fever in its earlier and later stages. 

 Not from urine or skin. It has 

 been isolated from blood of persons 

 dying from scarlet fever. Assumed 

 to be identical with streptococcus 

 isolated from diseased udders of 

 cows and from their milk. Found 

 by Klein in ulcerations of teats and 

 udders of certain cows. 



Morphology — A streptococcus ; poly- 

 morphic ; showing tendency to oval 

 and rod-shaped elements, especially 

 in impression preparations. Pres- 



ence of wedge - shaped, spindle - 

 like, rod - shaped elements in 

 agar and gelatine, and the char- 

 acteristic of coherent conglomera- 

 tion differentiate this streptococcus 

 from others of the same genus. 

 Irregularity in size and shape of 

 elements ; every transition between 

 coccus and bacillus. Coccus shape 

 prevails in bouillon, the bacillary 

 being more common on agar {see 

 Plate). 



Staining reaction — Simple stains and 

 Gram's method. 



Biology : cultural characters {includ- 

 ing biochemical features). 



Bouillon — At 37° C. after 24 

 hours, the medium remaining clear, 

 a single, thick, white-grey mass, or 

 several smaller masses, appear at 

 the foot of the tube ; coherent on 

 shaking the tube, floats through the 

 fluid medium as a flattened bun- 

 like body. Kurth pointed out that 

 when this mass was examined under 

 the microscope, a conglomerate 

 appearance was present. The 

 mass is cohesive. 



Gelatine plates and tubes — Slow 

 growth forming small grey colonies, 

 circular or oblong, with firm edge, 

 and consisting of closely-set coher- 

 ent mass of cocci. Older colonies 

 become nodular. Non-liquefying. 

 In gelatine at 37° C. the same 

 appearances occur as in bouillon, 

 but often more marked. Chain 

 formation from these cultures is 

 more marked than in ordinary 

 streptococcus. In gelatine at 37° C. 

 this organism grows similar to 

 S. longus. 



Agar plates and tubes — Three 

 types of colonies occur after 24 

 hours : {a) grey, granular, irregu- 

 larly-outlined tuberculated colonics ; 

 {b) colonies of similar kind, but 

 having confluent appearance with- 

 out tubercles ; {c) younger and 



