40 



CULTURAL STUDIES OF SPECIES OF PENICILLIUM. 



reddish. Colonies do not liquefy, or only slowly and partially liquefy, sugar gelatin, 

 Litmus reaction neutral, the shades of purple found abowt the turning point of litmus, 

 Colonies on apple are brighter yellow and produce ascigerous masses in very few days. 

 Received from Professor Thaxter, identified from the ascigerous form by Dr. C. 

 Wehmer. 



The author is convinced that Wehmer 32 is in error in attributing 

 a large, degree of polymorphism to this fungus. Numerous cultures 

 watched under all sorts of conditions are evidence that this species 

 does not produce prominent coremia or large masses of green conidia. 



CULTURAL DATA. 



Color white, but mycelium studded with yellow granules in acid media, with some- 

 times reddish areas and conidial green areas; reverse of colony yellow to orange; 

 color in media, pink in potato. 



Odor, none. 



Fig. 7. — Penicillium rubrum O. Stoll: a, 6, c, d, e, Whole conidiophores and the branching of conidial 

 fructifications (X 1,400); /, g, conidiiferous cells and conidial formation (X 1,400); h, j, sketch and diagram 

 of habit of growth (X 140); fc, sketches of old conidial fructification in large size (X 140); m, diagrammatic 

 figure (the successive series of conidial fructifications are produced by new branches from hyphae over- 

 growing the earlier series). (Drawn from gelatin culture, but found with approximately the same 

 morphology upon potato agar.) 



Fifteen per cent gelatin in water, medium growth; liquefaction none; litmus 

 reaction acid; potato agar and bean agar, mycelium transiently yellow, then color- 

 less or reddish or yellowish gray; potato plugs, white to gray, in parts yellow, potato 

 pinkish; Raulin's fluid, slow development, bright yellow colonies; Cohn's solution, 

 germination only. 



Synthetic fluid (Dox's), carbon supplied as: Cane sugar, good growth, yellow, up 

 to 30 per cent sugar, no growth at 50 per cent. Lactose 3 per cent, very slight growth; 

 lactic acid 0.9 per cent, very slight growth. Levulose 3 per cent, very slight growth. 

 Galactose 3 per cent, typical, acid reaction. Glycerin 3 per cent, germination only. 



