193 
be repeating much that I have said on a former occasion in a 
lecture on the “ Flora of Bath” read to the members of this Club 
some years back ;* and to which I refer my hgarers. I therefore 
pass on to the consideration of a more general question, perhaps 
also one of more general interest, viz., what are the causes that 
have operated—and which are still operating—to bring about the 
distribution of plants in the British Islands as we see them at the 
present day—some scattered about everywhere—others more or 
less collected in certain places far apart from each other, or, as 
happens in certain instances, confined to a single locality ? 
To solve this question two things must be taken into consider- 
ation. First, we mustremember the ages that have elapsed since our 
Islands received their first instalment of plants from the continent ; 
and then consider the multitude of causes that have been unceas- 
ingly at work to disturb them in the localities in which they first 
took root. Man, I imagine—after his own first appearance on the 
stage—has here been the chief agent. Think of the state of 
England at the present day. Thiuk of the large tewns and 
villages man has built—the former sometimes extending for miles 
‘into the surrounding country—to say nothing of manufacturing 
erections and tall chimnies, vomitting forth a black smoke 
deadly poisonous to very many plants—think of the thousands 
and thousands of acres given up to agriculture and gardening, all 
the native plants having been turned over or eradicated altogether 
—the heaths, commons, and various open spaces, from which 
nature has been expelled, and forced to make way for man and 
his artificial—as well as real—wants. Think again of the roads 
and railways running in all directions over the whole kingdom, 
like the web of some huge spider ; and, what is very curious, on 
the side embankments of some of these railways, you may occa- 
sionally stumble upon plants never seen nor met with before in 
the district—showing how they have been dispersed and hurled 
* Proceedings of the Bath Field Club, vol. 1., p. 25. 
