INTRODUCTION. 



15 



which Lichenology forms one, in particular ; while we are 

 satisfied that the idler, professional or amateur, voluntary or 

 non-voluntary, could not find a more pleasant as well as pro- 

 fitable means of dissipating ennui, and occupying a leisure 

 that must at times lie heavy on his hands. Nay, we may 

 go still further, and recommend it as a delightful relaxation 

 in the intervals of business or more severe study : in our 

 own experience we have found it so. Let it not be supposed 

 that we can recommend these pursuits merely as forms of 

 intellectual gratification to the individual engaged in them ; 

 they are capable of a more extended influence and applica- 

 tion. We believe that every observer, however humble his 

 sphere, and however meagre his opportunities, has it in his 

 power to contribute materially to the progress of science, 

 and to the development of its economical or practical appli- 

 cations, by the simple noting of matters of fact. JNTo group 

 of plants is more Protean in its characters than that of the 

 Lichens, — none more subject to structural alterations under 

 the influence of external circumstances. Hence the inves- 

 tigation of the innumerable phases or forms under which 

 species may occur — and without an accurate knowledge of 

 which all classification must be unsatisfactory and tempo- 

 rary — is a labour of almost insuperable difficulty to an in- 



