X Preface 



The imperfections of the book will be sufficiently 

 obvious to the reader. Some are at present unavoidable 

 owing to the unequal development of our knowledge of 

 the vegetation of different parts of the British Isles. While 

 some regions have been carefully explored and their 

 vegetation analysed, others have been only "reconnoitred," 

 and of others again, such as Wales and considerable parts 

 of Ireland, the plant-communities, as distinct from the 

 flora, are almost unknown. 



Most of the continental work on plant-communities 

 similar to or identical with British ones has been 

 deliberately neglected. A serious attempt, which will 

 eventually have to be made, to correlate British with 

 continental plant-communities would have involved a 

 task extending far beyond the immediate object in view. 



The Bryophyta, and the lower plants generally, are, 

 for the most part, mainly through want of knowledge, very 

 inadequately treated, and in the case of many plant 

 communities, ignored altogether. This is greatly to be 

 regretted, since these plants are frequently of the first 

 importance in differentiating plant-communities. The 

 algal associations of the freshwater aquatic formation are 

 scarcely touched upon. 



In a book of this nature, involving the correlation of 

 a great mass of unequally developed material from many 

 sources, it is inevitable that there will be numerous errors 

 and omissions. Great improvements mil be possible in a 

 second edition, especially having regard to the fact that 

 the subject is advancing very rapidlyj and the editor "\vill 

 be grateful for all criticisms and suggestions. 



The treatment of the ecological eifect of the diiferent 

 soils almost wholly lacks the basis which can only be 

 afforded by careful quantitative analysis and comparison. 

 Data of this kind are now being accumulated, but are not. 



