Phylum Inophyta [ 135 



send out branching filaments which become septate in such fashion that the ultimate 

 cells are binucleate. These cells form croziers and produce asci. During the develop- 

 ment of the ascogenous hyphae, other hyphae, more slender, grow up from the 

 vegetative mycelium; these produce a disk of undifferentiated cells below the layer 

 of asci, and send up sterile hairs (paraphyses) among them. 



Gaumann (1926) divided the families of this group into two series by the 

 presence or absence of a differentiated operculum at the summit of the ascus. The 

 names being put into neuter form, and family Tuberacea being added, the lists are 

 as follows: 



Inoperculata : Patellariacea, Dermateacea, Bulgariacea, Cyttariacea, Mollisi- 

 acea, Helotiacea, Geoglossacea, Tuberacea. 



Operculata: Rhizinacea, Pyronemacea, Ascobolacea, Fezizacea, Helvellacea. 



Along with these, Clements and Shear (1931) list eight families of lichen-formers, 

 some of them very numerous. 



Families Pezizacea and Ascobolacea include the ordinary cup fungi. They are 

 mostly saprophytes in soil or on manure, and do not usually produce conidia. Peziza 

 was listed by Fries first in order Cupulata; it is the evident standard genus of the order. 



Families Dermateacea and Helotiacea include many parasites on plants. One of 

 the Helotiacea is Sclerotinia cinerea, the agent of the brown rot of stone fruits. 

 As an active parasite it produces conidia of a type which, if the fruits were unknown, 

 would place it in the genus Monilia. These spread the disease rapidly. The killed 

 fruits fall and the organism lives in them as a saprophyte, replacing their tissues 

 with a hard black mass of hyphae, a sclerotium. This survives the winter and in 

 spring sends up stalked white apothecia. 



The Helvellacea have been treated as a separate order, but are not sufficiently 

 numerous and distinct to justify this treatment. They are saprophytes in soil, pro- 

 ducing large stalked apothecia bearing an extensive layer of asci which is everted 

 and wrinkled. The most familiar genera are Elvella and Morchella. The fruits are 

 edible, indeed delicious; they should be boiled briefly, then creamed and served on 

 toast. When found in abundance they should be preserved by drying for use through- 

 out the year. 



The Tuberacea, the truffles, also usually treated as a distinct order, produce 

 underground fruits which appear to be apothecia distorted and rolled into balls. 

 They are associated with particular species of trees on which the mycelia are be- 

 lieved to live as mycorhizae (Dangeard, 1894). The asci commonly contain reduced 

 numbers of spores. The fruits are prized by gourmands. 



The relationships of the Cupulata are a puzzle. Pyronema could be interpreted 

 as representing an evolutionary transition from the order Mucedines to this. Certain 

 parasitic cup fungi produce minute apothecia, hard, dark, and nearly closed, sug- 

 gesting a transition to order Sclerocarpa. Some species, particularly among the 

 parasites and lichen-formers, seem to intergrade with order Phacidialea, and thence 

 again both to Mucedines and Sclerocarpa. The operculate asci which mark a part of 

 the group occur also in other orders. Thus there is among Ascomycetes an appearance 

 of reticulate relationships, such as reputable naturalists of the past supposed to 

 exist in many groups. The appearance is of course illusory; sufficient study of other 

 groups has made it possible to distinguish the resemblances among them which indi- 

 cate relationship from those which are results of parallel evolution. The study of the 

 Ascomycetes has not yet been carried this far. 



