206 YEASTS AND MOLDS 
That part which is not submerged resembles a layer of velvet on the 
surface of the medium. 
Penicillium. Penicillium molds are important in the manufacture 
of certain cheeses. Thorn (1906, 1905) has given much study to this 
question. Dox (1910) has reported an extended study of the intracellu- 
lar enzymes in Penicillium camemberti. The following enzymes were 
demonstrated to be present: erepsin, nuclease, amidase, lipase, emulsin, 
Fie. 50.—Roquefort Penicillium (P. roquefortt). (After Thom, 1906.) 
a, part of conidiophore and of bas of fructification, highly magnified showing the production of 
basidia on the sides as well as at the apex of the basidiophore; 2, c, other types of branching; 
d, young conidiophore just branching; e, f, basidia and the formation of conidia, highly magnified; 
g,"h, j, diagrams of types of fructification as seen under low power (X80); 4.1, m,n, germination of 
coonidia and new conidia produced directly on the first hyphe. 
amylase, inulase, raffinase, sucrase, maltase, and lactase. The presence 
of these enzymes seems to indicate an ability to utilize various food 
products. Penicillia are widely distributed in nature and many of the 
molds which contaminate foods belong to this genus. Thorn (1910) 
has reported cultural studies on the species of penicillium. He has 
worked out a key which is of much assistance in studying molds and their 
relation to food spoilage. 
