CONTENTS. 



Page 

 Introduction 103 



I The Lichen Flora of Iceland 106 



II The Means of Propagation and Dispersal of the Iceland Lichens 130 



III The Biology of the Lichens of Iceland 137 



1 . Bark Lichens 137 



2. Epiphj'llous Lichens 142 



3. Karth Lichens 142 



4. Hock Lichens 156 



5. Synopsis of the chief Biological Conditions of the Lichens of Iceland 164 



IV The Classification of the Lichens into Associations 172 



1. Bark-Lichen Association 172 



2. The Earth-lichen Associations 174 



a. The Deserts 182 



h. Lichen-heaths 187 



c. Moss-vegetations 187 



d. The Grass Vegetation 191 



e. Heaths 197 



^H f. Coppices 217 



3. Rock-lichen Association 219 



a. Basalt 219 



h. Lava 224 



c. Tuff 227 



d. Liparite 22S 



V The Vertical Distribution of the Lichens 230 



VI The Abundance of Lichens in Iceland 234 



Bibliography 246 





