226 IMPORTANT VARIETIES OF FISSION- FUNGI. 



even in the cold, but not by Gram's method. The cap- 

 sules, which are colorless after the usual stain, may, how- 

 ever, be stained. (See Technical Appendix. ) 



Requirements as Regards Nutrient Media and 

 Oxygen. — Grows luxuriantly upon all the nutrient media 

 employed, both with and without oxygen. 



Gelatin Plate. — (a) Natural size. Superficial : Round 

 or roundish, moist, white colonies, with even border, 

 usually much elevated, rarely flat, with a slimy-fatty luster. 

 Deep : Roundish to whetstone-shaped, yellowish- white (15, 

 V). 



(6) Magnified fifty times. Superficial: Round colonies 

 with smooth border, reddish to yellowish-brown, trans- 

 parent only at the periphery. Sometimes there extend 

 outward from the center rays which appear as dark brown 

 thorns and points upon the lighter underlying part (15, 

 vn). Usually a structure can scarcely be distinguished. 

 Deep: Roundish to whetstone-shaped, smooth border, 

 brown, opaque (15, vi). 



Gelatin Stab. — Stab : Well developed, yellowish-white, 

 like a string of pearls. Surface growth : Elevated, like the 

 head of a nail. The gelatin is sometimes a little brownish 

 about the puncture, but never liquefied(15, u). 



Agar Plate and Stab. — Similar to the growth in gela- 

 tin, only the colonies are perhaps still more luxuriant and 

 moister. 



Sometimes we observed in plates, instead of the roundish deep col- 

 onies, single deep veil-like spreading colonies, some of which are 

 reproduced in Plate 15, vni. 



Agar Streak. — Growth spreading moderately, whitish- 

 yellow to gray, with a moist luster, much elevated, espe- 

 cially in the middle. The border is smooth, wavy, and 

 the periphery transparent. Water of condensation is 

 cloudy, with a slimy deposit (15, i). 



Bouillon Culture. — Very cloudy, with a slimy deposit 

 at the bottom, which upon shaking becomes homogeneous. 

 Bouillon becomes somewhat thickened. 



Milk Culture. — Not coagulated after twenty days. Abel 

 never found milk coagulated by true Bact. pneumoniae, 

 but the opposite was observed by others ; for example, 



