36 CULTUEAL STUDIES OF SPECIES OF PENICILLIUM. 



growth, evidently carbon deficiency. Lactic acid 0.9 per cent, better than lactose, 

 not typical colony, good color. Levulose 3 per cent, weak colonies. Galactose 3 per 

 cent, good growth, alkaline. Glycerin 3 per cent, weak growth. Alcohol, good 

 growth, becoming brown in age. Tartaric acid, very slight growth. Butterfat, rich 

 growth. 



Milk, growth good, alkaline to litmus; curdling (0.25 per cent of calcium chlorid 

 added) in 10 days; digestion, fairly rapid; color in milk, none. 



At 37° C, no growth; grew when cooled; check at 20° C., good colony. 



PENICILLIUM PURPUROGENUM O. Stoll. 



Beitr. z. morph. u. biol. Char. Penicillium, Wiirzburg, 1904, p. 32, t. I, fig. 6; t. Ill, 

 fig. 2; t. IV, fig. 3. 



Colonies on lactose gelatin and potato or bean agar, gray-green to brown or olive, 

 deeper green upon cane-sugar media, closely floccose, almost velvety in surface 

 appearance, spreading slowly over the substratum and producing in the whole mass 

 of medium a red color. In acid media rich in sugar secondary floccose mycelium arises 

 white or with hyphae studded with yellow granules. Conidiophores 100-300 by 3.5/*, 

 arising separately or from portions of hyphse just above the surface of the substratum. 

 Conidial fructification 50-100/t in length, composed of one verticil of branches (some- 

 times with a secondary or partial secondary verticil), bearing whorls of conidiiferous 

 cells 11-12 by 2.5/x, narrowed abruptly to form sterigmata at the apices. Chains long, 

 divergent. Conidia elliptical, 3.4-3.8/( by 2-2. 5/x, green, granular, with from one to 

 several small highly refractive granules in each, in chains falling apart in fluid mounts. 

 Colonies liquefy sugar-gelatin slowly in 15 to 20 days. 



Received from Krai in Prague. 



The authority for the name of this species is attributed by Saccardo 

 to Otto Stoll, as here indicated, since his description, or rather dis- 

 cussion, of this fungus forms the basis of Saccardo's Latin diagnosis. 

 Stoll quotes the name from Krai, who gives the author as Alex. Fleroff, 

 in Warsaw. Stoll has given the first discussion that is in any way 

 adequate. 



A closely similar organism has been found by Prof. F. D. Heald 

 upon corn (Zea mays) in Nebraska. A third form corresponding 

 closely in morphology and many cultural characters was sent from 

 Miami, Fla., by Professor Rolfs. Although distinguishable by some 

 characters, these forms resemble P. jyurpurogenum as described above 

 so closely in morphology and cultural characters as to justify including 

 them, temporarily at least, under this name. Neither of these forms 

 produces the purple color as rapidly or as purely as the original 

 race of P. imrpurogenum. 



CULTURAL DATA. 



Color gray-green, becoming dark green with the presence of cane sugar; reverse 

 yellow to reddish, or colorless; color in media, none to red to deep purple, almost black, 

 according to medium; odor, none. 



Fifteen per cent gelatin in water, medium growth, characteristic fruiting; liquefac- 

 tion, partial in cultures 3 weeks old, or none, none in 10 to 12 days; litmus reaction, 

 slowly alkaline or often neutral. Potato agar and bean agar, good colonies but no 

 purple color, purple produced when sugar is added. Potato plugs, mycelium yellow 



