LINDSAY, ON LICHENS. 197 



sometimes pycnidiferous states of lichens are found just as 

 spermogoniferous states are — without either of the other 

 forms of reproductive organs. 



" The distinction between pycnides and spermogones is, to a 

 certain extent, one of convenience — one depending on the 

 difference in character of the contained corpuscles — not one 

 as yet founded on essential differences in function, inasmuch 

 as the function of neither can yet be said to be thoroughly 

 established or understood. Hence it may hereafter appear 

 that some organs now denominated pycnides should be really 

 regarded as spermogones, as those of Peltigera and Alectoria, 

 and perhaps, though less likely, the converse, — that some 

 organs now regarded as spermogones should be looked upon 

 as pycnides, as those of Lichina ! " 



The spermogones and pycnides of the crustaceous lichens 

 will be treated of in a future memoir. In the mean time we 

 are glad to find that Dr. Lindsay has undertaken to publish 

 a ' Synopsis of British Lichens/ in which we understand the 

 lichens will be nature-printed, and accompanied with drawings 

 of their microscopic structure, by the author. 



