584 THE DEUTEROMYCETES (FUNGI IMPERFECTI) 



Many imperfect fungi are pathogenic to plants and sporulate 

 on the plant organs only while these organs are still alive. After 

 the death of the tissues, conditions may be favorable for the pro- 

 duction of the perfect stage, which such species may be found to 

 require for hibernation. Other species, however, produce co- 



Fig. 148. Types of fructifications among Fungi Imperfect!. A. P\'cnidium. 

 B. Acervulus. C Conidiophores protruding separatelv from stoma. 

 D. Sporodochium. E. Synnema. F. Penicillate conidiophore. G. Capitate 



conidiophore. 



nidia as readily on decaying plant organs as on living ones. Such 

 species may be able to survive from one season to the next with- 

 out the presence of a perfect stage. It must be remembered, 

 however, that survival of the conidial stage throughout the ^\'in- 

 ter in no way determines, so far as is now known, the production 

 of the perfect stage. 



Many imperfect species, although placed in the same form 

 genus, are totally unrelated, as becomes evident when their per- 

 fect stages are taken into consideration. On the other hand, a 

 structural parallelism between the conidial stage and ascomyce- 

 tous stage is known to exist [Orton (1915)]. Evidence in sup- 



