646 MINNESOTA BOTANICAL STUDIES. 



dark- colored or black, the Stilbeae in which the sporophores 

 are collected into a stipe, and the Tubercularieae in which the 

 sporophores are collected in a waxy or gelatinous wart-like 

 head or tuft. The last two groups are very natural ones, and 

 have been retained with some internal alterations. But the 

 two former are often so difficult to distinguish, even by Sac- 

 cardo's characters, and do such violence to obvious relation- 

 ships, many times splitting up genera solely because of color, 

 that they cannot be accepted as he has constituted them. So, 

 also, his subdivision of the families according to the septation 

 of the spores does too much violence to plain relationships to 

 be maintainable, even if entirely reliable as a key. 



The forms included in the Muceclineae and Dematieae of Sac- 

 cardo fall readily into a number of what may be called tribes, 

 based upon the sporophores. These fall into two higher groups, 

 in one of which the sporophore is well developed and usually 

 much-branched, while in the other it is less developed, and 

 either scarcely to be distinguished from the conidia or at most 

 simple and rigid. If objection be made to this arrangement as 

 making it more difficult for one unfamiliar with the genera to 

 place them readily, it may be answered that the latter function 

 belongs not to a systematic arrangement, but to an artificial 

 key or synopsis. The best current dispositions of the larger 

 groups, — such as the Black fungi, e. g., — are open to the same 

 objection. For the former of the two groups last mentioned 

 we have retained the name Mucedinaceae. For the latter we 

 should have been glad to use the name Dematiaceae. But, as 

 Dematium cannot be included in the group, we could not well 

 do so. 



The nomenclature of families and other groups above genera 

 is not settled. In the absence of rule or authoritative usage to 

 determine such matters, we have employed the first name used 

 to designate a group corresponding to the one in question in 

 some degree, altering the termination to conform to prevailing 

 usage. In the nomenclature of genera and species we have 

 followed the Rochester Rules. 



Where forms commonly included in the Hyphomycetes have 

 been shown to belong to autonomous groups, we have omitted 

 them, so that the reader will miss Microstroma, Myxotrichum , 

 Ceratium, and many other familiar genera. In the same way 

 we have omitted Aspergillus and Penicillium. They have a 

 proper place elsewhere, and we see no reason why those forms 

 in which ascus - fructification is yet unknown should not be 



