8 



THE HIGHER FUNGI: CARPOMYCETEAE 



THE fungi that have been the subjects of discussion in the foregoing 

 chapters are frequently designated as the Lower Fungi or Phyco- 

 myceteae (excluding the Mycetozoa) in contrast to the often much more 

 highly developed forms usually designated as the Higher Fungi or Carpo- 

 myceteae. It may be well here to contrast the two groups as to their main 

 points of difference, recognizing that though these distinctions are in 

 general valid yet there are many forms of Higher Fungi in which these 

 differences are not recognizable. 



Structure 



1. The Phycomyceteae are prevailingly tubular coenocytes, non- 

 septate except at regions of injury or where reproductive organs are cut 

 off from the rest of the mycelium. (Exceptions may be noted in old aerial 

 mycelium of some Mucorales and in most Entomophtlorales.) The simpler 

 members of this class may consist of single cells. The Higher Fungi are 

 cellular, i.e., their hyphae are divided by septa into true cells, usually 

 uninucleate or binucleate. (Exceptions are numerous. Thus old cells 

 sometimes become multinucleate; on the other hand, many young hyphae 

 from germinating spores or young ascogenous hyphae may delay the 

 formation of cross walls for some time. Aside from these, numerous 

 species are scattered throughout the whole group in which almost all the 

 cells are plurinucleate.) 



2. In the Lower Fungi sexual reproduction leads to the formation of a 

 single, usually thick-walled, oospore or zygospore. In the Higher Fungi, 

 wherever true sexual organs or processes can be distinguished, the union 

 of sperm and egg, or of cells substituted for these, leads to the production 

 of a many-celled structure, called by Sachs (1874) a "spore-fruit," all 

 the cells of which may become the reproductive cells (as the ascospores 

 in the asci of the order Saccharomycetales) or of which only a part are 

 reproductive cells, the remainder being necessary components of a more 

 or less complicated fruit body (e.g., the sum of the ascogenous hyphae 



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