INTRODUCTORY EXPLANATIONS. 55 



six appear most true to nature, — that is, to the actual pe- 

 culiarities of vegetable distribution in Britain. 



It may, however, be admitted that in limiting our atten- 

 tion to the island of Britain exclusively, some of the species 

 must be referred to types of distribution, under which they 

 would not be placed if our views took in a larger geo- 

 graphical space. Hence, caution and consideration will 

 be requisite in any attempt to connect these types of distri- 

 bution in Britain with others formed upon more extended 

 views ; as will be shown afterwards. 



In connexion with this subject, it has become requisite 

 for the writer of the present work to take some public 

 notice of certain views brought before the attention of the 

 British Association, by Mr. Edward Forbes, on occasion 

 of their meeting at Cambridge, in 1845; and which, by 

 several reports, by a subsequent lecture in London, as also 

 by a more lengthened essay in a geological work, that 

 gentleman has endeavoured to advertise into publicity and 

 credence. In his communication to the British As- 

 sociation Mr. Forbes had made free (if unacknowledged) 

 use of the former labours of the writer of this volume ; and 

 in so doing he took to himself credit for results and gene- 

 ralisations which had truly originated with the author of 

 the present work. But not wishing here to interrupt the 

 regular course of his ' Explanations,' by the introduction 

 of comments on the opinions or conduct of Mr. Forbes, he 

 will add the view which he feels authorized and compel- 

 led to take, in reference to Mr. Forbes's publications in 

 the matter, as an Appendix at the end of this volume. 



