

FUNGI IN CHEESE RIPENING. III 
Penscillium rogueforti (nomen novum ).*—Colonies quickly 
turning green, becoming a dirty brown in age, velvety strict, 
indeterminately spreading by large main radiating, branching 
hyphae giving a somewhat uneven or indefinite margin, which 
gets a white, fibrous, almost spider-web appearance from its 
alternation of submerged parts of hyphae with short prostrate 
aerial loops; reverse of colony yellowish white. Conidiophores 
arising separately and in acropetal succession from the growing 
parts of submerged hyphae (comparatively few from aerial 
parts, but some), 200-300 septate. Fructification go-120 p or 
at times 160 by 30-60p at broadest place, usually appearing 
double by the divergence of the lowest branch, branchlets 
(basidiophores ) irregularly verticillate bearing crowded verti- 
cils of appressed basidia, 9-11 by 2.5m, with long divergent 
chains of conidia. Conidia-bluish-green, cylindrical to globose, 
smooth, rather firm walled, 4-5 in diameter, germinating by 
a straight tube. Colonies do not liquefy sugar gelatine though 
they soften it somewhat. Fungus changes litmus from red to 
blue very rapidly and strongly almost from the beginning of 
growth. Fruiting period short, but one crop of spores upon 
the mycelium. Cosmopolitan and omnivorous, or nearly so. 
Characteristic of Roquefort and related types of cheese. Fig. 2. 
OIDIUM LACTIS. 
The mold variously known as Oidium or Oospora lactis is 
another cosmopolitan organism. ‘This fungus differs widely 
from the species previously described. Inoculated into any 
suitable medium it grows with enormous rapidity. A single 
spore (or oidium) may give rise to several centimeters of my- 
celium and hundreds of spores in twenty-four hours. It prefers 
very moist situations, since almost the entire mycelium is de- 
veloped below the surface of the substratum. It is therefore 
passed unnoticed many times or produces changes which are 
attributed by the observer to bacteria. Description therefore 
must depend upon microscopic characters. ‘The study of the 
border of the young colony shows numerous vegetative hyphae 
radiating outward. Each of these is found to divide dichoto- 
mously (fig. 3, a, b) so that the border is a crowded series of 
forking branches. In the older parts of the mycelium a branch 

* The mold of Roquefort cheese is referred to in the literature only as P. glaucum. 
Careful study shows that this species has been confused with numerous others under 
the name P. glaucum. The unique position of this mold and its very distinct characters 
make it very desirable to have the name proposed above, Penicillium roqueforti. 
