PREFACE TO THE FIRST EDITION. 



Though Britisli Algology has for several years, at leisure 

 hours, been a favourite study of mine, I should have been 

 afraid to undertake this introductory work had I not been 

 encouraged by Dr. Greville of Edinburgh, and Professor 

 Harvey of DubHn. The former lent me books, gave me 

 advice, and allowed me to avail myself of his . published 

 works ; the latter gave me counsel, allowed me to take aid 

 from his pubKcations, and solved my doubts respecting 



plants I sent him. 



In describing the Corallines I was glad to avail myself of 

 the accurate descriptions given by my excellent friend Dr. 

 Johnston. In the fresh-water department, I was happy to 

 draw on. my friends Mr. Ealfs and Mr. Hassall. Mrs. 

 Grifaths, with her characteristic kindness, granted me the 



