144 IMPORTANT VARIETIES OF FISSION-FUNGI 



Often single members present larger dimensions and the 

 form of a club i. e., to a large sphere is attached a small, 

 thin neck-piece. These are not, however, resting forms. 

 (Compare Stolz, C. B. xxiv, 337.) 



According to Kruse and Pansini and our own investiga- 

 tions, all transitions up to the Strept. pyogenes occur, so 

 far as concerns the form of individuals and the structure 

 of chains. (Compare also Biriaghi, " Ueber einen Strept. 

 capsulatus," C. B. xxn, 273.) 



Relation to Oxygen. Facultative anaerobe. 



Intensity of Growth. Grows fairly rapidly but not 

 luxuriantly at 37. At ordinary temperature (22) very 

 slowly, and more often not at all. 



Gelatin Plates. (a) Natural size. Superficial: Round- 

 ish, dim, diffusely gray, transparent colonies, which after 

 four days have attained a diameter of from 1 mm. to 2 mm. 

 Deep: Very small, roundish, whitish-gray (2, v). 



(6) Magnified seventy times. Superficial: Circular or 

 roundish colonies with almost smooth border, colorless, 

 and delicately granular. They are often so delicate that 

 with the narrowest diaphragm the periphery can hardly 

 be differentiated from the surrounding medium (2, vm, e). 

 Deep : Round, sharply outlined, slightly more granular 

 (2, vin, i)- 



Gelatin Stab Culture. Stab : At first thread-like, later 

 resembling a string of pearls; growth faint. Superficial 

 growth : Minimal, almost none (2, i). No liquefaction. l 



Agar Plates. (a) Natural size: Like gelatin plates 

 (2, v). 



(6) Magnified fifty times. Superficial: Roundish, almost 

 even border, at times somewhat fringed, delicately 

 punctate, a little more compact than the gelatin culture, 

 colorless, perfectly transparent (2, vi). Deep: Roundish 

 or whetstone-shaped, almost even- bordered, opaque, gray 

 to grayish-black, more coarsely punctate than the super- 

 ficial (2, vii ). 



Agar Stab. Stab: Thread-like, whitish-gray (2, in). 



1 MacCallum and Hastings have described a liquefying form (analo- 

 gous to certain rare varieties of the Strept. pyogenes) as Micr. zymo- 

 genes (C. B. XXV, 384). 



