434 



BOTANY OF THE LIVING PLANT 



mycelium permeates any nutritive medium ; thus they serve lor the 

 quick spread of the Mould. The corresponding conidiophorcs of 

 PeniciUiuvi 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 branch 

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



The alternative method of propagation follows in Aspergillus on 

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



Fig. 367. 

 I, Section through part of .1 Iniit of Pejiicilliiii)! ; a, b, pscudo-parcnchjTnatous 

 covering; i^^ascogenous hyphac. 2, 3, ascogenons hyphac with isci, more highly 

 magnified. 4, ascosporcs. (.\ftcr Brefcld.) 



described under the name of Eurotium. When ripe each contains 

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

 Penicillimn, but more rarely. The development originates in either 

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

 an antheridium. As in Spliaerotluca 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 

 l)y the surrounding tissue, anrl produce the numerous oval asci, 

 each with eight ascospores. In PeiiiciUimti the structure of the 

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



