30 The North American Cup-Fungi 



present themselves in order to secure a convenient arrangement 

 and trust that, to some extent at least, they may also be an 

 index to natural relationship. 



But what do we mean by superficial and fundamental char- 

 acters? Superficial characters are those which may be easily 

 detected by the casual student who does not have access to a 

 fully equipped laboratory or even compound microscope and 

 must rely largely upon a hand-lens or the naked eye in making his 

 determinations of the species. The presence or absence of the 

 operculum in the ascus may be regarded as a fundamental 

 character but, as has already been shown, this rather obscure 

 character is accompanied by several other more superficial ones 

 which will enable the student to place the species in the proper 

 group without actually seeing the operculum. It is not possible 

 in every case to identify a species in the present group absolutely 

 without the use of a compound microscope, but in many cases 

 they may be placed in the proper section or in the genus and 

 occasionally even referred to the species. 



Superficial characters are often a sure index to more funda- 

 mental ones and there is no reason why they should not be used 

 by the taxonomist, although there may be a great difference of 

 opinion as to which should or should not be employed. The 

 protrusion of the ascus was at one time used but at the present 

 time is considered of no value as a taxonomic character. Whether 

 the hymenium is exposed from the first (gymnocarpous) or is 

 at first enclosed by the apothecium (angiocarpous) has been 

 made a good deal of in the past but it does not now seem to have 

 any particular value. 



No attempt has been made here to revolutionize the classifica- 

 tion of the cup-fungi, although it has been somewhat modified 

 to suit the author's own ideas. No doubt a much better one 

 may be devised in the future, but in the meantime the one 

 employed here will serve as a medium through which our ideas 

 regarding species of cup-fungi occurring in North America can 

 be transmitted to the student. If this can be done it will have 

 served its purpose. 



The term cup-fungi or Discomycetes is used to include those 

 ascomycetes in which the hymenium is freely exposed at maturity. 

 On this character, the cup-fungi merge into the Hysteriales and 

 Phacidiales although generally the term is restricted to the 

 Pezizales. Following Boudier's suggestion, the entire group is 



