64 British Fungi. 



only expressed by the manner in whieli the pilous of 

 an agaric is arrano^ed in the vounor state, the colour 

 of the hymenium of a Peziza, or the change in colour 

 of latex when exposed to the air, and such characters, 

 as far as they go, appear to be quite as constant, and 

 thereiore as useful in the discrimination of separate 

 forms as any of the characters used by the modern 

 school of bioloofists. Of course the above characters do 

 not indicate in the least degree the difference between 

 true species as generally understood and form-species, 

 and this indeed is the weak point in the system 

 adopted by the followers of Fries. The labours of the 

 modern school, initiated by Tulasne, De Bary, and Bre- 

 feld.liave to a great extent remedied this defect of tlieir 

 predecessors, and by pure cultures have clearly de- 

 monstrated in numerous instauces that the " species " 

 founded by Fries and his followers are but inde- 

 pendent phases in the life-history of other forms. So 

 far the biologists have done good, inasmuch as they 

 have indicated the apparently only sure method of 

 determining what is a species, and consequently cor- 

 recting the mistakes of the earlier school, or rather in 

 adding enormously to the stock of knowledge already 

 possessed by the Friesian disciples, for surely the last 

 mentioned body must have added something to our 

 knowledge of the nature of fungi, although their 

 earnest endeavours are too often treated with scorn 

 by the present generation, and perhaps nowhere do 

 we see such, gross abuses of brilliant discoveries as 

 are perpetrated by some of the followers of De Bary. 

 Take the example of lieterocism in the case of Puc- 

 cinia graminu-, which was demonstrated by De Bary to 

 the satisiacticn of everyone not saturated with preju- 



