Persoon was in his day, to express any doubt as to his knowledge ot 

 his subject. 



I think there have been three men in Europe who have made a 

 serious study of the European Polyporoids in general, viz: Persoon, 

 Fries and Bresadola. I do not mean to say there have been only 

 these, for there have been others, but these are the three who have 

 published most on the subject in general. In my account of the 

 specimens in Persoon's herbarium, I have in many cases added notes 

 made in Fries' herbarium, or learned from my correspondence with 

 Bresadola. 



Fig. 331. 



Labels from Persoon's herbarium. 



The following species, most of which are well known to-day and 

 well known to Persoon, are not represented by specimens in his 

 herbarium. I include here the species with which, from his writings, 

 he was familiar in the woods but of which he did not preserve speci- 

 mens. If our lawmakers decree that species are not valid unless 

 preserved by Persoon (as Professor Durand argues in the case of 

 Geoglossum viscosum), then if we obey the laws we must give up 

 some very familiar species. The following is the list : 



Leptocephalus, nummularius, umbellatus, giganteus, imbricatus, cristatus, 

 spumeus, candidus, triqueter, croceus, destructor, mollis, caesius, stypticus, 

 crispus, officinalis, levis, fraxineus, dryadeus, marginatus, pinicola, tristis, vitreus, 

 holoporus, xylostromeus, brumalis, fuligineus, melanopus. 



465 



