The Present Flora of Britain. i j 



plants which are confined to a few widely separated 

 localities. Some of the LiliacecB and Boraginece, for 

 instance, though abundant where they occur, are curiously 

 local, most of them being absent from extensive areas 

 apparently as well suited for their growth as those in 

 which they are found. In the altered state of our woods 

 these anomalies are particularly difficult to understand, 

 for the plants usually do not appear to group themselves 

 into assemblages confined to special districts, and the 

 distribution of each species has to be studied separately. 

 Not one of our woodland mollusca or plants, unless the 

 Arbutus be reckoned as a forest species, falls into the 

 special groups confined to the eastern counties, to Cornwall, 

 or to the West of Ireland. It is a question whether the 

 absence of Lusitanian woodland species may not be due 

 merely to the destruction of forests in Cornwall and in 

 the West of Ireland; but this cannot be determined till the 

 sub-fossil plants of the forests buried under the recent peat 

 in these districts have been collected and examined. It is 

 possible that some of the difficulties may be cleared up 

 when we have studied each patch of ancient woodland, 

 however small ; for by searching small isolated patches of 

 old forest we can often find outliers of the sedentary wood- 

 land mollusca and plants, such as probably once extended 

 over wide areas now bare or under cultivation. 



A certain number of our plants are confined to lime- 

 stone rocks or to calcareous soils ; but it will be sufficient 

 here to remark that none of them is characteristically 

 eastern or western, and that scarcely anything is yet 

 known of any of them in the fossil state. 



In addition to these classifications according to climate 

 or habitat, there is yet another, certain species being 

 eastern and others western. Though we have a con- 



C 



