BASIDIOMYCETES 421 



Moller attitude rests upon the external similarities which exist between 

 basidia and conidiophores, and consequently conceives the basidia as 

 conidiophores which have become constant in form and spore number. 

 The Bary hypothesis, at the time of its foundation, rested mainly 

 upon intuitive considerations and, after the death of its creator, was 

 not further developed until recently. We will proceed through the 

 series to the more important points of discussion. 



The haploid mycelium of the Basidiomycetes possesses the same 

 characteristic habit as that of the Ascomycetes, but it is considerably 

 more highly developed than that of the higher Zygomycetes which has 

 hardly developed beyond the coenocytic stage. 



The imperfect forms of the Basidiomycetes show a striking resem- 

 blance to those of the Ascomycetes and those of the Phycomycetes ; thus 

 the Oedocephalum type is common to all three. 



The sexual organs cannot present any direct points of discussion as 

 they are lacking in the Basidiomycetes. An extensive separation of plas- 

 mogamy and caryogamy occurs, however, in all the higher Ascomycetes 

 while it is only suggested in the Phycomycetes. In the Zygomycetes, 

 pseudogamous plasmogamy is unknown, while in certain Ascomycetes, it 

 is the rule. 



Since plasmogamy and caryogamy coincide in time and space or 

 follow each other directly in the Phycomycetes, they lack the dicaryo- 

 phase which is so common in the Basidiomycetes and which appears in 

 the ascogenous hyphae of the Ascomycetes. One only has to imagine that 

 in the Pyronema type, the internodes arising from the outgrowth of the 

 hook hypha between two hook formations become longer, and one 

 obtains a Basidiomycetous hypha as shown in Fig. 272. In the Basidio- 

 mycetes, the complicated apparatus which is connected with the forma- 

 tion of the ascogenous hypha has disappeared and the close relationship 

 which exists between clamps and asci is less apparent with the great 

 increase of the clamp containing mycelium and of a more vegetative 

 character. Although the forms without clamps may be explained thus, 

 or by derivation from the Plicaria type, there is still more to the matter. 

 In any case, the clamp formations would be incomprehensible if one 

 could not explain them as a relic of the Ascomycetes. 



Because of the lack of dicaryophase, zeugites are unknown in the 

 Phycomycetes, whereas in the Ascomycetes they precede the young ascus 

 in the form of hook hyphae. 



From these considerations it appears probable that the Basidio- 

 mycetes stand closer to the Ascomycetes than to the Phycomycetes; the 

 derivation from the latter leads to great cytological difficulties while the 

 derivation from the former is based upon many analogies. The critical 

 question is whether one should consider the basidia derived from conidio- 

 phores or from asci. 



