532 



Class BASIDIOMYCETES. 



Order Ustilaginales. (Smuts.) 



Order Uredinales. (Rusts.) 



Order Tremellales. (Gelatinous fungi.) 



Order Hymeniales. (Mushrooms, etc.) 



Order Gastrales. (Puff balls, etc.) 



In case the slime moulds and Bacteria are not to be relegated 

 to the domain of animal life, as has been time and again suggested, 

 they would properly form classes lower than the Phycomycetes, 

 vh. : MYX0MYCETP:S with the Order Acrasiales, Plasmodio- 

 phorales and Myxogastrales ; and SCHIZOMYCETES with the 

 Orders Eubacteriales and Myxobacteriales. * 



There still remains the systematic position of the Lichens. 

 Since the coordination of the orders of the entire phylum Thal- 

 lophyta is far from being settled owing to the limitations of our 

 knowledge, and since the two main series, separated from each 

 other by physiological rather than structural or morphological char- 

 acters, are held apart largely as a matter of convenience, it may be 

 better to likewise hold the lichens apart as a separate group, 

 though the reasons therefor are much less apparent than in the 

 separation of the algae and the fungi. The lichens are distinc- 

 tively fungi and there is no more real reason for holding them 

 apart from the fungous orders with which they intergrade than 

 there would be in separating other parasitic forms in distinct series 

 because of some supposed mutualism between the parasite and its 

 host. The fact that the lichens have been treated apart from 

 their real alliances has doubtless been the cause of some part of 

 the confusion relating to them. The orders Pyrenolichenales, 

 Discolichenales, Hymenolichenales and Gastrolichenales may 

 therefore be sandwiched in among their nearest alliances in the 

 conspectus. If held apart in a distinct series it must be under- 

 stood as a matter of expediency and convenience and not an indi- 

 cation of natural affinity among diverse groups such as they really 



are. 



9 December, 1896. 



*Cf. Thaxter, Bot. Gazette, 17: 389-406. D 1892. 



