FUNGI AND FUNGOUS DISEASES OF PLANTS 245 
growths of the mildew. Another complex method of reproduc- 
tion results in forming a heavy-walled body, the ascocirp, SO 
called because it is the body which contains the sacs and asco- 
spores (fig. 190). In late summer the ascocarps may, without 
magnification, be seen as small black bodies upon the surface 
of lilac leaves. When the ascocarp is broken, the sacs and 
spores are exposed. From the walls of the ascocarp peculiar 
arms extend, and in the lilac mildew and some related mildews 
these have strikingly branched tips. 
The heavy-walled ascocarp is resistant 
to unfavorable climatic conditions. It 
may pass through the winter and break 
open in the following spring, thus free- 
ing the thin-walled sacs. Upon escaping 
from the sacs the spores may be blown 
or carried about and germinate upon 
new host leaves. 
233. Blue mold or green mold. When 
old shoes, gloves, or other articles made 
of leather are left in damp, warm places, 4... 191, The blue mold 
a blue or green mold (Penicillium) fre- 4. left is the Aba 
quently develops upon them. This mold _ hypha, with the character- 
also grows upon old lemons and oranges, oe ee 
and upon cheese. Various species have the right are germinating 
distinctive shades of color, so that the spores: Much magnified. 
After Thom 
common names of blue mold or green 
mold can be taken only as applying in a general way. Certain 
species of Penicillium are said to give characteristic flavors to 
the cheese in which they grow, as Penicillium Roqueforti of 
Roquefort cheese and Penicillium Camemberti of Camembert 
cheese. These species are widely distributed and are found 
growing upon many substances besides cheese.) Penicillium 
1 An interesting discussion of various species and their cultural reactions 
is ‘Cultural Studies of Species of Penicillium,’’ by Charles Thom, Ph.D., 
Mycologist in Cheese Investigations, Bulletin 148, Bureau of Animal Indus- 
try, U.S. Dept. Agr., 1910. 
