226 SOME NEW BOOKS [September 



present state of psychological nomenclature it seems open to an author to define 

 any term in accordance with his special predilections. We think, however, that 

 the majority of reasoning men believe that the process demands a due compre- 

 hension of that subtle relationship among thoughts which we symbolise by 

 .•. or v But this is perhaps because it is consonant with our own special 

 predilections. C. LI. M. 



A WELCOME WORK. 



The Origin of the British Flora. By Clement Reid, F.R.S. 8vo, pp. vi. 

 + 191. London: Dulau and Co., 1899. 



Few works on the British flora possess greater interest or importance than 

 this, which deals with the evidence gained during recent years from investiga- 

 tions into the vegetable remains of the later Tertiary and the Post-Tertiary 

 deposits in Britain. These investigations rest mainly on the work of Mr. Reid 

 himself, ably supplemented by Mr. James Bennie and other' careful observers. 

 Their results have been published through varied channels ; and Mr. Reid has 

 laid all interested in the flora of Britain under an obligation by bringing these 

 results, and a good deal of other information, within easy reach. The author is 

 peculiarly well fitted to perform such a work. Long-continued personal researches 

 in Britain have been supplemented by wide acquaintance with the labours of 

 others, both in Britain and throughout the north of Europe. He has produced 

 a book that will do much to stimulate others to extend the work and to fill the 

 gaps in the record in so far as that can be done. One part Mr. Reid might have 

 extended with advantage to the recruits that the book is likely to enlist. The 

 hints that he has given as to the most productive localities, and the methods of 

 preparation of plant remains from the Tertiary and the Post-Tertiary deposits in 

 Britain, make one feel how helpful a fuller treatment of both topics would have 

 been. His remarks about the difficulty of obtaining fruits and seeds of existing 

 plants with which to compare the fossils, emphasise strongly how imperfect 

 herbaria are, as a rule, in the provision of complete examples of these parts. 



The introductory chapters deal with the leading peculiarities and divisions 

 of the existing British flora, the means of dispersal of the seeds met with among 

 its members, and their consequent fitness for ready distribution ; the changes in 

 the form of the islands and their relation to the continent of Europe in former 

 periods, and the evidences of changes of climate and their influence on the flora. 

 A careful study of these chapters will aid much in arriving at clear views of the 

 true nature of the problems involved in explaining " the origin of the British 

 flora," and in accounting for its more marked peculiarities when compared with 

 the floras of the adjoining countries. 



Next follows an enumeration of the various localities in Britain (arranged 

 alphabetically) from which these fossils have been recorded, with a notice of the 

 probable age of each deposit, and a list of the species identified from it. Some 

 continental localities are similarly treated. Then comes a list, in systematic 

 order, of all existing British plants that have been identified as fossils, with a 

 list under each of the localities in Britain in which it has been found fossil, or 

 on the European Continent, if not yet found fossil in Britain ; and the age of each 

 plant as a fossil is given. The chief facts under this are briefly summed up in 

 a "Table showing the range in time of the British Flora." 



It is no mere form of words to say that the book is indispensable to all who 

 wish to gain a clear conception of the nature of the British flora. This is evident 

 from a single perusal of its pages ; but its full value will be realised only after 

 frequent and continued reference. Only six species, no longer found in a wild 

 state in Britain, have as yet been identified with certainty as living in our islands 

 in the later Tertiary or Post-Tertiary times. These are :• — Acer monspessulanum, 

 Trapa nutans, Salix polaris, Picea excelsa, Naias graminea, J¥. minor. A 



