AS A SPECIFIC CHABACTER IN LICHEITS. 63 



I canwo^, then, commend chemical '* characters " to the con- 

 fidence of the lichenologist. At the same time I hold that a 

 botanical diagnosis ought to be based on all the characters at the 

 command of the observer, including those which are cliemical. 

 And, though I believe that characters dravrn from morphology, 

 gynaecology, anatomy, and physiology must ever stand in the fore- 

 ground, it would be wrong in the lichenologist not to avail him- 

 self of any assistance that may, in certain exceptional and diflScult 

 cases, be supposed to be afforded by chemical reaction in dia- 

 gnosis. I am very far from desiring to depreciate chemistry as an 



concerns 



Lichens, I believe their chemistry is as yet in far too crude and 

 unsatisfactory a state to warrant us in expecting any assistance 

 that can be relied upon from colour-reaction in the determination 

 of species ! 



