THE ENTOMOLOGIST. 



Vol. XIV.] DECEMBEE, 1881. [No. 223. 



SOME THOUGHTS ON THE DISTRIBUTION OF THE 

 BRITISH BUTTERFLIES. 



By F. Buchanan White, M.D., F.L.S. 



Accustomed as we are to the rich vegetation with which most 

 parts of the British Islands are to-day clothed, we are apt to 

 forget sometimes that at no very distant geological period the 

 whole country was totally destitute of all plant-life, and conse- 

 quently, as a matter of course, uninhabitable by any animals. It 

 is probable, however, that, soon after the present flora came in, 

 the animals which derive their sustenance from it made their 

 appearance, and we may be sure that amongst the earliest 

 would be plant- eating insects, and more especially the Lepi- 

 doptera. But it is almost certain (though we have no direct 

 evidence of this) that certain kinds of plants would precede other 

 kinds, and it is therefore likely that the insects would come in 

 like order, and follow the plants on which they fed. If, therefore, 

 we can arrive at some conclusions as to the order in which the 

 plants came, we shall be able to discover one factor in the distri- 

 bution of the insects. There are, however, other factors whose 

 effect must have been, and still is, very great ; and to discover 

 these offers a very interesting problem. 



The British Rhopalocera and their present distribution in 

 these islands at the present day may be stated thus : — 



2m 



