CHAPTER XIV 



HIGHER FUNGI 



SUBCLASS MYCOMYCETES 



The higher true fungi are characterized by a mycelium in which the 

 hyphae, as a rule, are permanently multicellular by the formation of trans- 

 verse septa dividing the hyphal length into short cells. Some mycolo- 

 gists, among them Brefeld, think it important to call the fungi which 

 are transitional between the Phycomycetes and the Mycomycetes 

 proper by the name MESOMYCETES, but the distinction between 

 these intermediate forms and the higher fungi, being at times difficult 

 to make, the writer has thought it best not to use the name MESOMY- 

 CETES, as that of a subclass. The student will see the justice of this 

 viewpoint as the discussion proceeds. 



Of unsatisfactory position in the fungous system are two families 

 of fungi, which Brefeld includes in the subclass MESOMYCETES, 

 which will illustrate his point of view as to transitional forms. Under 

 HEMIASCINEiE, as a suborder, he includes the families Ascoideace^e 

 and ProtomycetacEtE. Engler considers that these families have a 

 doubtful systematic position. They show affinity to the PHYCOMY- 

 CETES, and yet, they have septate hyphae and a sporangium, known 

 as an ascus, which contains an indefinite number of spores, hence their 

 closer affinity to the fungi of the order ASCOMYCETALES. The first 

 family is represented by Ascoidea ruhescens which lives on wounded 

 beech tree trunks, particularly in the sap which flows from the wounds. 

 It forms a brown felt-like growth. The richly septate hyphae cut off 

 laterally and terminally conidiospores and sporangia are formed in 

 a series, so that as the numerous derby-hat-shaped spores are dis- 

 charged and the sporangium is emptied of its contents a new sporangium 

 forms inside of the walls of the old one, so that ultimately a sporangium 

 may appear to arise out of a receptacle with a wall composed of three 

 or four layers. In old cultures, the fruit-bearing hyphae may be united 

 to form Coremia. The genus Dipodascus belongs to this family. The 



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