434 



BOTANY OF THE LIVING PLANT 



mycelium permeates any nutritive medium ; thus they serve for th< 

 quick spread of the Mould. The corresponding conidiophores o 

 Penicillium are constructed on a similar plan, but are much smaller 

 Instead of bearing a mop-like head, they are repeatedly branched 

 giving them a brush-like appearance, while from the end of each brand 

 a chain of conidia is abstricted, as before (Fig. 366). 



The alternative method of propagation follows in Aspergillus or 

 a rise of temperature, and results in those yellow fruits originally 



2. 



FIG. 367. 



i, Section through part of a fruit of Penicillium ; a, b, pseudo-parenchymatous 

 covering; rf=ascogenous hyphae. 2, 3, ascogenous hyphae with asci, more highly 

 magnified. 4, ascospores. (After Brefeld.) 



described under the name of Eurotium. When ripe each contains 

 numerous asci, and spores. Similar fruits are formed also in 

 Penicillium, but more rarely. The development originates in either 

 case from a spiral or twisted carpogonium, which is associated with 

 an antheridium. As in Sphaerotheca these sexual organs become 

 enveloped in a pseudo-parenchymatous covering, derived from 

 the mycelium that bears them. The carpogonium divides into a 

 number of cells, from which strong hyphae arise. These are nourished 

 by the surrounding tissue, and produce the numerous oval asci, 

 each with eight ascospores. In Penicillium the structure of the 

 fruit-body is more complicated than in Aspergillus (Fig. 367). In 



