BACILLUS ANTHRACIS. 309 



little elevated, roundish. Deep : Punctiform and perma- 



(ently small (35, n). The structure is the same as given 

 )r the agar streak. 

 (b) Magnified fifty times : Deep and superficial colonies 

 resent great differences. The former are usually whet- 

 ;one-shaped, roundish, greenish-gray, becoming yellowish 

 toward the center. The peripheral zone consists of coarse, 

 dark-colored, crumbly masses, which are continued as 

 shorter or longer outgrowths, composed of little hairs, 

 crumbs, and granules. If the colonies lie near the surface, 

 outgrowths are formed at the periphery which resemble 

 hairs or locks of hair (35, I, i). The same completely 

 surround the surface colonies (35, i, e). The colony then 

 gives the impression of a ball of wool or tangled hair of a 

 yellowish-gray color. 



(c) Magnified 150 times. Superficial colony : The curly 

 hairs appear as exceedingly long threads, which at the 

 periphery lie singly, and toward the interior in parallel 

 collections. These are regularly arranged like locks of 

 hair (often intertwined like a whip-cord) (35, in). Deep 

 colonies: The outgrowths of the deeply located colonies 

 present coarsely granular, very irregular clumps, which 

 are usually connected by means of nodular branches and 

 fine processes. The colony does not present any center 

 proper, but is very irregularly torn and exceedingly poly- 

 morphous. 



Agar Stab. — From the stab canal, which remains 

 white, there extend outward longer or shorter hairs, which 

 become shorter as they are lower in the stab, and which 

 terminate at times in curls or small clumps (34, vu). The 

 surface growth is roundish, regularly spreading, with a 

 smooth border, a little elevated, with a fatty luster, and 

 gray, bluish, or yellowish-white in color. After a longer 

 time there is often observed a formation of concentric 

 zones (34, ix), or also, in other cases, of distinct, radiating 

 folds passing outward from the center (34, viii). 



Agar Streak. — The growth remains limited to the in- 

 oculation streak; smooth edge, usually wavy. The color 

 is grayish-white, somewhat transparent at the edge. The 

 entire growth impresses one as if there were innumerable 

 tiny, silvery air-bubbles lying beneath the surface. The 



