52 CULTURAL STUDIES OF SPECIES OE PENICILLIUM. 



CULTURAL DATA. 



Color white, through cream to a shade of gray-green upon sugar media, without 

 sugar gray or drab, all becoming drab when old (exposure to light); reverse of colony, 

 uncolored, cream; media, uncolored. 



Odor, none, except in very old cultures upon milk or cereal. 



Fifteen per cent gelatin in water, moderate growth, not rich; liquefaction, none, 

 or slow and partial after 2 to 3 weeks in acidified cultures; litmus, strongly alkaline; 

 colonies slow, moderate growth, typical. Potato agar and bean agar and potato plugs, 

 fair, white to gray colonies lacking or nearly free from green color. Raulin's fluid, 

 very heavy growth, white through pronounced cream to green shades. Cohn's solu- 

 tion, slow growth, characteristic, but lacking in green color. 



Synthetic fluid (Dox's), carbon supplied as: Cane sugar, characteristic, abundant 

 green color in solutions as high as 50 per cent, acid. Lactose 3 per cent, characteristic, 

 acid reaction. Lactic acid 0.9 per cent, slowly typical, with ultimately an alkaline 

 reaction to litmus. Levulose 3 per cent, slowly typical. Galactose 3 per cent, char- 

 acteristic growth, very slowly developing the typical green color. Alcohol about 5 

 per cent, characteristic. Potato starch, characteristic . Malic acid 1 per cent, fair 

 colony, colorless. Butterfat, slowly typical colony with a tinge of violet in reverse, 

 no color in fluid. 



Milk, typical growth; curdling (0.25 per cent calcium chlorid added) in 10 days; 

 digestion, slow but fairly complete; color in milk, none. 



Camembert cheese, capable of reducing moist curd soured by lactic organisms to a 

 semiliquid condition. 



At 35° to 37° C, no growth; at 20° C, excellent. 



PENICILLIUM CAMEMBERTI, var. ROGERI Thorn, n. var. 



Syn. P. candidum of Roger and Maze, not Link. 



Colonies grown upon sugar gelatin or bean or potato agar pure white, loosely and 

 evenly floccose to the very margin, where aerial and submerged hyphee grow with 

 equal rapidity. Reverse of colonies white or yellowish white (not discolored). Co- 

 nidiophores 3-5 by 100-800/.! varying greatly, mostly branches of aerial hyphse. Conidial 

 fructification 70-90/1 in length, loosely and irregularly branched and bearing rather 

 few basidia at unequal heights, with divergent chains of colorless conidia. Branch- 

 ing system of conidial fructification sometimes 75/* in length. Conidia smooth, 

 hyaline, 4^.5 or even 5.5/* in diameter, globose or nearly so when ripe. Sugar gelatin 

 is slowly liquefied under the center of the colony only, colonies never floating in a 

 pool of liquid. Reaction in the medium is acid to litmus at first, then changes to 

 alkaline. 



This fungus has been found by the author only upon Camembert, 

 Brie, and Xeufchatel cheeses from western Europe. 



This variety has been discussed by Maze 13 as P. candidum Link. 

 This seems an impossible application of the name P. candidum from 

 Link's description n or that given by Saccardo, since the spores are 

 stated to be 2-3// in diameter. Further, in such identifications no 

 account is taken of a paper by Morini/ 6 in which an ascigerous stage 

 is described for P. candidum Link. Under four years of cultivation 

 no signs of an ascigerous form have been produced. Stoll 2i has consid- 

 ered P. candidum to be only a colorless P. glaucum, but as the author 

 has so far failed to find a worker who will undertake to limit the name 



