GRASSES OP IOWA. 



113 



Penicillium glaucum. — This is one of the 

 most common of all our moulds and is 

 easily recognized by theglaucus green color 

 it produces on the surface. At first a white 

 mycelium spreads over the surface of the 

 seed. It starts usually in the hilar regions. 

 The mycelium, through an enzyme action, 

 undoubtedly, dissolves the starch. Raised 

 masses are formed on the surface. These 

 consist of masses of fungus thread strands. 

 The strands send out lateral branches, 

 _ from the end of which a whorl of short 



Fig. 61. Common blue branches appears, as shown in figure 35. 



mould {PeniciUium glau- i. t. ' o 



cum). Spores at end of Thesc give rise to One or more whorls. 



branches; spores borne 



In chains. (Pammei and Prom the ultimate branches a chain of 



King) 



small spores is produced, the last one in. 

 the chain being the oldest. 



The ascospores have not been found in corn, but occur in 

 poorly lighted places and are produced in the absence of 

 oxygen. The spores produced in chains germinate when the 

 required amount of moisture and heat is present, so that 



unlimited numbers of genera- 

 tions may proceed from a 

 single spore. These spores 

 also preserve their vitality for 

 a considerable length of time. 

 Brefeldf has shown that they 

 will germinate though kept in 

 a dry place for several years. 

 Eurotium {Aspergillus) glau- 

 cus DeBary. — This species is 

 common in stored corn, and 

 will be referred to in connec- 

 tion with a disease of cattle. 

 '^'^^^^''g^(^^l^JS5^'<*^/^i'A^('S^c The mycelium of this fungus 

 ^^^yi^^'^f^^^C^^Qs^- ^ spreads over the surface of 

 ^CJ>:^^-^'^^rl7n0^^^^{ ^^® corn, in the hilar regions. 

 jP^^^ The bracts surrounding the 

 grain are the special points of 

 /j.^- ^.^-.^T^® ^"^l^o**"™ °^ ^*^^''i°^ ^*5^® attack. Prom this point the 



of PeniclUlum glaucum consisting of a ^ 



hard compact mass. The ascl and asco- hilar ICgion is attacked. The 



spores shown above. (Brefeld ) ^ 



tUntersuchang. u. Schimmelpllze. II and IV. 



