AS A SPECIFIC CHABACTEB IN LICHENS. 51 



and 



manufacture of lichen-dyes — that, while bleaching-solution gene- 

 rally gives no reaction, ammoniacal maceration developes the pig- 

 ment known as " Cudbear ^'^ on which account the lichen has been, 

 and still is, larffely used as a dye-eavlnfi: stuff *. " We distineruish 



greatest facility (Nyl., p. 361) 



gata and revolufa, which have been so often confounded," the 

 latter giving an erythrinic reaction " whilst the Icdvigata and 

 sinuosa do not present the least trace of this reaction" (p. 362). 

 Schaerer's No. 612, and Hepp's No. 581, which (according to Nyl., 

 loc, cit,) are really P. revoluta^ both gave me a blood-red ; but in 

 the former I found the reaction with potash not to be permanent. 



while in the latter it was so. 



permanency 



potash-reaction is a "new criterion," quite as valid for " sepa- 

 rating" these lichens into different species as the various " cri- 



of Nylander and Leighton ! In several specimens of Iwvu 



( 



Mudd's Exs. 69) 



specimen of the same plant from the Pass of Leny, blood-red 

 was developed by bleaching-solution. In other forms o? sinuosa 

 I sometimes met with an erythrinic reaction, sometimes not. 

 The differences in reaction described by Nylander do not prevent 



me assigning, as formerly, both revoluta and Icevigata, 

 number of other lichens, to the single type sinuosa. 



** The reactive demonstrates in the most decided 



. . . . . that P. olivetorum is a species perfectly distinct from 



perlata^ with which it has been hitherto imited" (Nyl., p. 361). 

 He admits, however, that "certain organic differences without doubt 



marks 



diffi 



to verify than the chemical difference here noted ; so that we must 

 no longer confound them, as has been hitherto done in all the 

 Herbaria, since the most inexperienced person is now able to dis- 

 tinguish them by means of the reactive " (p. 361). The medulla 

 of P. olivetorum is represented as giving an erythrinic reaction, 

 while that of perlata does not. I have, however, obtained a 

 blood-red, though pale, by friction, in Australian forms oi perlata. 

 I have had no opportunity of testing authentic specimens of 



» Vide paper by the author " On the present Domestic Use of Lichen-Dye- 

 stuffs in the Scottish Islands and Highlands," Seemann's Joum, of Botany, 



1868 



i:2 



Tvynci^ru 



