CHAPTER XVIII 

 FUNGI IMPERFECTI 



The many fungi whose life cycle is little known are usually grouped as 

 Fungi Imperfecti. From its origin, it is obviously a large artificial group of 

 more or less unrelated species. In this work I have removed from the Fungi 

 Imperfecti all those genera where there seemed reason to believe that they 

 were closely related to other genera whose whole life cycle is known; e.g., 

 the group usually called Monilia by medical men has been removed to the 

 Eremascaceae Imperfectae, although it is quite possible that when the life 

 cycles of these species are better known, some may be found to belong else- 

 where. I have placed the dermatophytes in an appendix to the Gymnoascaceae, 

 although only one species has yet been found to produce asci. Similarly the 

 species of Aspergillus and Scopulariopsis, in which no perithecia have yet been 

 demonstrated, have been placed in the Aspergillaceae. Even after all these 

 groups have been removed, there remain several important genera whose rela- 

 tionships with the Ascomycetes are still obscure. It is possible that many of 

 these species represent degenerated lines in which asci never will be produced, 

 but in the last 50 years so many species have yielded to improved cultural 

 technic and media that it seems probable that eventually many more may be 

 placed. Hence, the Fungi Imperfecti are conceived as a temporary dumping 

 ground until the gaps in our knowledge have been filled. 



The older authors attempted to divide the group on the basis of color and 

 then septation of spores. They divided the Fungi Imperfecti into several 

 groups on the basis of the elaborateness of the fructification in which the 

 conidia were borne. Of these, only those groups in which the spores are borne 

 in coremia or on more or less differentiated conidiophores without protection 

 from sterile tissues need be considered here. For our purposes, even the 

 presence of coremia has little importance. The Hyphomycetes, in which we 

 are interested, were next divided upon the basis of color of spores into the 

 Mucedineae with light colored or hyaline spores and the Dematieae with black 

 spores. While this differentiation is often useful, it is very artificial and 

 difficult to apply in certain well-defined groups. Further division was based 

 on the conidiophore and septation of the spore. This system culminated in 

 the complete and elaborate works of Saccardo, and of Lindau and his German 

 coworkers. Even with this system, the Mucedineae with unicellular spores 

 and undifferentiated conidiophores were not well studied, yet it is in these 

 groups that the genera of most interest to the medical man are to be found. 



In France, largely due to the work and influence of Vuillemin, the dif- 

 ferences between blastospore, arthrospore, and conidium in the narrower sense 

 have been emphasized. To him we also owe the concept of phialide as a highly 



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