100 



THE ACTINOMYCETES, Vol. II 



III. Aerial mycelium light carmine to brown- 

 ish. 



1. Sporophores in verticils. 



a. Sporophores straight or wavy. 



19. Streptomyces ne- 

 tropsis 



b. Sporophores in spirals. 



20. Streptomyces tendae 



2. Sporophores not in verticils. 



a. Sporophores si raighl . 



21. Streptomyces vene 

 zuela( 



b. Sporophores in spirals. 



a 1 . Spirals at end of long, straight 

 sporophores ; melanin-positive. 



22. Streptomyces laven - 

 dulae 



b 1 . Spirals different; melanin-nega- 

 tive. 



a'-'. Spirals closed. 



23. Streptomyces vio- 

 laceoniger 

 b 2 . Spirals open. 



a 3 . Spirals regular, usually 

 >5 turns. 



21. Streptomyces fra- 

 ilnii 

 b 3 . Spirals irregular, usually 

 <5 turns. 



25. Streptomyces ery- 

 thraeus 



IV. Aerial mycelium ash-gray. 



1. Sporophores in verticils. 



26. Streptomyces reti- 

 culi 



2. Sporophores no1 in verticils. 



a. Sporophores straighl or wavy. 



\ 



^"H* 



Figure 28. Sporogenous coiled hyphae of Streptomyces T 3 IK); taken from a blue sector of a colony 

 (Reproduced from: Duggar, B. M. et al. Ann. X. V. Acad. Sci. 60: 71-85, 1954). 



