376 



THALLOPHYTES 





substratum, and sends up conidiophores at the ends of which the 

 conidia are borne in radiating chains as shown in Figure 326. 

 The spores are scattered mostly by the wind. 



The sex organs appear a little later than the conidia and 

 consist of two short hyphal filaments which come together and 

 intertwine spirally. One of these filaments represents the oogo- 



nium and the other, the antheridium. 

 After fertilization, ascogenous hyphae 

 develop from the ascogonium and bear 

 eight-spored asci at their tips. In the 

 meantime other hyphae grow up from 

 below the ascogonium and a closed case 

 or cleistothecium is 

 formed, within which 

 are the asci inter- 

 mingled amongst 

 sterile hyphae. The 

 walls of the asci 

 finally dissolve, thus 

 setting the asco- 

 spores free within 

 the cleistothecium. 

 Through the decay 



of the wall of the cleistothecium the spores are 

 finally freed to be scattered by the wind. 



Another Ascomycete which sometimes 

 poisons livestock is the Purple Monascus. 

 It belongs to another order and is a simpler 

 Ascomycete than Aspergillus. It is often 

 present in moldy silage and when fed to live- 

 stock may cause death. This mold produces 

 a purple pigment which colors the substratum 

 upon which the mold lives and distinctly colors 

 silage attacked by the Mold. 



Penicillium. A common species of Penicillium is the Blue 

 Mold which develops on shoes or gloves left in damp places, and 

 on lemons, cheese, etc. It often occurs intermingled with Bread 

 Mold on bread. The conidia are borne as shown in Figure 327. 

 Its sexual reproduction is similar to that of Aspergillus and the 

 cleistothecia are about as large as a coarse grain of sand. 



FIG. 327. A species of 

 Penicillium, showing conidi- 

 ophores bearing chains of 

 conidia. 



DOQ 



FIG. 328. *A 

 naked -ascus Fun- 

 gus, Taphrina pruni 

 on a plum, showing 

 the asci developed 

 without any cover- 

 ing on the surface 

 of the epidermis 

 (X400). Redrawn 

 with modifications 

 from Strasburger. 



