ASPERGILLUS 



375 



higher Red Algae, such as Polysiphonia, for as the ascogenous 

 hyphae develop from the ascogonium, sterile hyphae, growing up 

 from below the ascogonium, form a compact hard wall which 

 makes a case for the asci and ascospores, just as the filaments 

 growing up from below the 

 carpogonium produce a case 

 for the carpospores in Poly- 

 siphonia. 



The Blue and Green Molds 

 (Plectascales) . S u p e r fi- 

 cially these Molds resemble 

 the true Molds discussed 

 under the Mucorales, but 

 their spore masses are gen- 

 erally green or blue, while 

 those of the true Molds are 

 black. There are about 250 

 known species in this order, 

 but they are saprophytes and 

 only a few of them are of 

 much importance. They 

 bear their ascospores in 

 closed ascocarps or Cleisto- 

 thecia. Aspergillus and 

 Penicillium are two familiar 

 genera of the order. 



Aspergillus. These Molds 

 are commonly green on ac- 



FIG. 326. A species of Aspergillus. 

 A, a portion of a mycelium, showing a 

 conidiophore bearing chains of conidia 

 (300); B, sex organs coiled about each 

 other and consisting of hyphse similar 

 in appearance; C, the cleistothecium 

 which develops after fertilization and in 

 which the asci develop (X 200). 



count of their greenish spore 

 masses. One form known 

 as the Herbarium Mold is 

 troublesome in herbariums 



where it attacks specimens that are not well dried. They 

 often occur along with the true Molds. They will grow 

 on cheese, leather, wall paper, fruit, hay, silage, and on 

 most any damp object from which they can obtain nourish- 

 ment. Some are poisonous and stock are injured and 

 sometimes killed by eating them in moldy Corn, hay, and 

 silage. 



The loose extensive mycelium runs over and through the 



