FAMILY PHAGACEAE 



1139 



and its strain RWl are ineffective in neu- 

 tralizing this bacteriophage. 



Immunological relationships : Cultures 

 of host-strain R, after exposure to this 

 bacteriophage, furnish subcultures only 

 partly resistant to this bacteriophage and 

 completely susceptible to streptococcus 

 bacteriophage RW and its substrain RWl . 



Literature : Whitehead and Hunter, 

 Jour. Path, and Bact., U, 1937, 337-347. 



29. Phagus streptococci H. {loc. cit., 

 158). From generic name of host. 



Common name : Streptococcus bacterio- 

 phage RW. 



Host : Streptococcus cremoris Orla-Jen- 

 sen, strain RW. 



Geographical distribution : New Zea- 

 land. 



Induced disease : Plaques 0.25 to 0.6 

 mm in diameter. 



Thermal inactivation : At 70° to 75° C, 

 time not recorded, probably 30 minutes 

 (pH6.0). 



Literature : Wliitehead and Hunter, 

 Jour. Path, and Bact., U, 1937, 337-347. 



Strains : One variant has been described 

 and distinguished from the type variety, 

 typicus H. {loc. cit., 158) : 



29a. Phagus streptococci var. virilis H. 

 {loc. cit., 158). From Latin virilis, vig- 

 orous. Common name: Strain RWl of 

 streptococcus bacteriophage RW. Dif- 

 fering from the type variety in being able 

 to increase at the expense of strain RWl 

 of Streptococcus cremoris (Whitehead and 

 Hunter, Jour. Path, and Bact., 44, 1937, 

 337-347). 



30. Phagus maculans spec. nov. From 

 Latin maculare, to speckle, in reference 

 to tiny plaques produced by this bac- 

 teriophage . 



Common name : Streptococcus bac- 

 teriophage A. 



Hosts : Streptococcus 646, 751, 775. 



Geographical distribution : United 

 States (Massachusetts ) . 



Induced disease : Plaques exceedingly 



minute, scarcely visible to the unaided 

 eye. 



Serological relationships : Specific anti- 

 sera neutralize but there is no cross reac- 

 tion with respect to streptococcus bac- 

 teriophage B, C, or D. 



Thermal inactivation : At 60° C in 1 

 hour. 



Other properties : Withstands storage 

 at about 5° C for at least 145 days with 

 but little loss of virulence. 



Literature : Evans, Science, 80, 1934, 

 40-41; U.S.P.H.S., Public Health Re- 

 ports, 49, 1934, 1386-1401. 



31. Phagus lacerans spec. nov. From 

 Latin lacerare, to tear, in reference to 

 ragged edges of plaques produced by this 

 bacteriophage. 



Common name : Streptococcus bac- 

 teriophage B. 



Hosts : Streptococcus 563,639 : Strepto- 

 coccus mucosiis Howard and Perkins. 



Insusceptible species : Streptococcus 

 erysipelatos Rosenbach. 



Geographical distribution : United 

 States (Wisconsin). 



Induced disease : Medium size plaques, 

 the largest about 3 mm in diameter, edges 

 ragged, centers clean. 



Serological relationships : Specific neu- 

 tralization, but no cross reactions with 

 streptococcus bacteriophages A, C, 

 andD. 



Thermal inactivation : At 60° C in 1 

 hour. 



Other properties : Withstands storage 

 at about 5° C for at least 261 days. 



Literature : Clark and Clark, Jour. 

 Bact., U, 1926, 89; Proc. Soc. Exp. Biol, 

 and Med., U, 1927, 635-639; Colvin, 

 Jour. Inf. Dis., 51, 1932, 17-29; Evans, 

 U.S.P.H.S., Public Health Reports, 49, 

 1934, 1386-1401; Jour. Bact., 39, 1940, 

 597-604; Shwartzman, Jour. Exp. Med., 

 46, 1927, 497-509. 



32. Phagus tolerans spec. nov. From 

 Latin tolerans, tolerating, in reference to 

 the unusual ability of this streptococcus 



