ORIGINAL COMMUNICATIONS. 



On Polymorphism in the Fructification of Lichens. By 

 W. Lauder Lindsay, M.D., F.R.S. Edinburgh, F.L.S. 

 London. 



About ten years ago I made the secondary or complemen- 

 tary reproductive organs of Lichens a subject of special study, 

 submitting to careful and repeated microscopical examination 

 several thousand specimens from all parts of the known 

 world. The fruits of these researches have as yet only been 

 partly published, and that mostly so far as relates to the higher 

 Lichens. I was struck with the discovery of many instances 

 of what I have been since led to regard as Polymorphism in 

 the fructification — plurality in the reproductive organs — of 

 Lichens. I refer here more especially to the occurrence in the 

 same species of more than one form, of Spermogonium or Pycni- 

 dium. I hesitated, however, to publish my results for various 

 reasons, and, inter alia, because — 



I. The observations in question, if correct, are a novelty 

 in lichenology. 



II. I distrusted the correctness of my observations, re- 

 ferring the multiple forms of Spermogonia and Pycnidia 

 in question to various Fungi unknown, which did not exhibit 

 their ordinary fructification in the specimens examined by me. 



But since that date I have repeatedly met with instances of 

 the same multiple forms of secondary fructification in con- 

 nection with Lichens only; my comparative study of 

 Lichenoid Fungi has led me every year to discover further 

 and closer links of connection between the Fungi and 

 Lichens ; I see less and less reason to doubt that the same 

 plurality of reproductive organs which characterises Fungi 

 may to a less extent equally characterise Lichens ; and I have 

 been more and more led to assign the subjects of my observa- 

 tions to Lichens, in connection with which they occur, rather 



VOL. VIII. NEW SER. A 



