60 Bibliographical Notice. 



arguments advanced by Mr. Watson ; and it must be allowed that 

 many of the theories advocated by other writers besides Forbes rest 

 too much upon negative evidence : this is especially true where use 

 has been made of geological data. Perhaps it may be wiser to adopt 

 the course recommended in the • Cybele,' to postpone for a while our 

 inquiries into the origin and age of species, and to collect hopefully 

 the materials for the future edifice, rather than attempt to rear it 

 upon an insecure foundation. 



What we read in this volume of the distribution of the British 

 flora is no bad example of the different groups into which the plants 

 of a country may be subdivided according to individual fancy. 

 Forbes saw five main groups, which he considered distinct in age as 

 well as in character. Henfrey gives four, without touching upon the 

 question of age. Watson has six "types," with a seventh to be 

 added for the West Irish plants ; and it also appears that the writer 

 who acknowledges the greatest number of groups is the one who is 

 least inclined to grant a distinctness in age. 



Now, leaving out of question the alpine species, the actual features 

 of the British flora are not very different from what might have been 

 expected if the entire lowland vegetation were of uniform age. If we 

 have upon our western shores many of the local and characteristic 

 plants, is not the climate of the west coast quite exceptional as regards 

 Europe? If the so-called "Iberian" plants of the west of Ireland 

 were originally western species, peculiar to the outskirts of their 

 continent, would not the wasting of the land leave just such charac- 

 ters as we now find ? As the sea advanced, so would the " mari- 

 time" climate, and so would its appropriate plants be gradually driven 

 back upon their outposts, till they found a last refuge upon the 

 mountain slopes and shores of western Europe — more isolated, too, 

 as being most exposed to the inroads of the sea. Of whatever date 

 their origin, the species characteristic of the edge of a continent must 

 naturally be sought at its circumference. Mr. Watson has allotted 

 the species to their several " types " according to their distribution 

 within Great Britain only. Still it may be said, roughly, that we 

 should look among the "Atlantic" (even more, the "Hibernian") 

 rather than the "Germanic," to the western rather than to the 

 eastern side of Britain, for plants that may have once had their 

 "metropolis" in this country. We have thought it necessary to 

 give the more prominence to these considerations because it is so 

 much the fashion to adopt as an axiom the necessity of a different 

 epoch for every different " flora," that few care to incur the charge 

 of being unphilosophical by venturing to question the correctness of 

 this view. 



But to return to the volume before us, the fourth of the ' Cybele 

 Britann^ca.' Its author thus speaks of the nature of his task : — 



" So many subjects crowd upon the attention in commencing this 

 fourth volume, that it becomes really difficult to answer the questions, 

 as to which of those subjects are to be treated at any length, which 

 of them can be slightly noticed only, and which of them must be 

 passed over entirely. References to the works of other writers, where 



