IV PREFACE. 



lively Quaker when reproved, by a graver brother, for his witticisms : 

 " Friend, if thou knew how much I keep in, thou wouldst not find fault 

 with what I let out." And if you, dear Critic, could know the number of 

 puzzling forms of Algae which in the course of the last five years have 

 passed through my hands, and which I have had to reduce to their specific 

 types, you would judge leniently of my mistakes, where I may have been 

 deceived by such forms, and wrongly proposed them as new species. 



Whatever may be my errors in this respect, I have the satisfaction to 

 know that the study of British Marine Botany has been fostered and ex- 

 tended by this work ; and this, to an author who feels a personal interest 

 in his subject, is the best reward for his labours. A progressive taste has 

 shown itself for these plants, in the large increase of collectors within the 

 past five years, and in the number of my correspondents since the monthly 

 issue commenced. Many new species have been discovered, and several 

 others added to the British list ; and several, which had not been gathered 

 for many years previously, have been rediscovered, some in new habitats, 

 and some in their old, but lost, stations. Very few of these discoveries 

 or additions have been made by myself, but are due to the zeal of my cor- 

 respondents, a majority of whom, familiar as I am with their handwriting 

 and friendly feeling, are personally unknown to me. 



To those kind correspondents I would now return my most grateful 

 thanks. Their number is too great to particularize every name, and I dare 

 not trust myself with naming many, lest I might accidentally omit some 

 valued friend ; — but there are a few to whom I cannot omit a further ex- 

 pression of gratitude for their unwearied assistance, and the essential 

 service they have rendered to me. And first I would express my deep 

 obligation to my invaluable friend Mrs. Griffiths, to whose contributions 

 almost every page of these volumes bears witness, and without whose 

 assistance many rare species could not have been properly illustrated. To 

 my kind Plymouth friends, the Eev. Mr. Hore, Dr. Cocks, Mr. Bohloff, and 

 Mr. Boswarva, I am indebted for many hundreds of beautifully preserved 

 specimens. To Miss White and Miss Turner I owe almost all my ac- 

 quaintance with the Algse of the Channel Islands, and the latter lady has 

 added more than one new species to our list. To Eev. Mr. Pollexfen 

 and Dr. M'Bain I am indebted for Orkney Algse ; and to Miss Warren, 

 Miss Ball, Miss Gifford, Miss Cutler, Mrs. Gatty, Mrs. Gulson, Mrs. 

 Hayden, Rev. Dr. Landsborough, Dr. Dickie, Mr. Ralfs, Eev. Mr. Cress- 

 well, &c, for specimens of the rarer Alga? of their respective neighbour- 

 hoods ; and to these, and all other kind friends, whether enumerated in this 

 place or in the body of the work, I would now record my obligations of 

 gratitude for their liberal communications and sympathy. 



W. H. H. 



Trinity College, Dublin. 

 July 30, 1851. 



