CLASSIFICATION OP THE MOLDS 



65 



acteristie flavor and consistency of these cheeses is due in 

 large measure to the growth of these PenicilUa. 



Some hundreds of species of Penicillium have been de- 

 scribed. They are comparatively difficult to identify 

 because of the variation in the appearance of the same mold 



Fig. 44. — Penicillium. 

 oamembertii. 



1. PemoilUum roquefortii. 2. Penicilliwm 



when grown under different conditions. A few species may 

 frequently be determined from the food or substratum on 

 which they are growing. The following key to such species 

 has been adapted from Thom.^ 



1 U. S. Dept. Agriculture, Bureau of Animal Industry, Bull. 118. 

 KJEY TO Some Common Species of Penicillium 

 A. Growing on cheese. 

 B. Camembert or Brie. 



C. Floccose colonies, white to gray- 

 green Penicillium camembertii. 



00. Powdery colonies, yellowish- 



■nrhite P- irevicwule var. glabrum. 



CCC. Forming yellow-brown areas, 



spores rough P- IreviowuZe. 



BB. Roquefort, forming green, streaks 



inside cheese P- roquefortit. 



AA. Growing on citrus fruits (lemons, 

 oranges ) . 



B. Mold colonies blue-green P. italicum. 



BB. Mold colonies olive-green. P. digitatum. 



