6 INTRODUCTOEY OBSERVATIONS. 



fectly understood or traceable; and in turn it is itself 

 still changing, and still advancing to something different 

 for the future. 



The Mstory of past changes, in so far as those changes 

 tend to explain the present existence and distribution of 

 plants, might be deemed within the proper scope of 

 phyto-geography. But such a history is unwritten as 

 yet for the botany of any country ; although some natu- 

 ral records of the past have been brought to light by 

 geological research ; and it may also be said, that others 

 of a more recent character are now accumulating in a 

 printed form. Both kinds of records may eventually be 

 rendered available by our successors. But the few phi- 

 losophical botanists in England at the present time, may 

 well regret that printed records of real value have only 

 been commenced so very recently. And the deficiency 

 of reliable records, anterior to very recent dates, seems 

 equally the case with respect to the botany of other 

 countries, as it too truly is the case with respect to that 

 of Britain. 



If any books had been printed in the times of Gerarde 

 and Ray, or even so late as the earlier career of Hudson 

 and Smith, with objects similar to those of the Cybele 

 Britannica, we might now be in possession of records 

 much more serviceable to geographic botany. Successive 

 accounts of the then actual condition of British vegeta- 

 tion, one and two centuries ago, examined from the same 

 points of view as attempted in this treatise, would have 

 possessed high value and interest in their utility to the 

 science of the present day. And if the reliability of the 

 various records, and the scientific competence and trust- 

 worthiness of the recorders, had been taken into account 

 then, as freely as is done with regard to more recent 

 writers, — for example, in the volumes of this present 



