88 THE entomologist's rrcokd. 



complete insularity of Great Britain, is, I believe, generally admitted, 

 and it seems probable that the area was then colonised to its fullest 

 capacity — that is, till a point of equilibrium was reached between the 

 forces of immigration and the antagonistic influence of the competition 

 of already existing forms, limitations imposed by flora, and so on. 

 Also that, since complete insularity was ettected, but few additions 

 have been made by purely natural means. Species, no doubt, over a 

 continental area are continually altering, extending, or reducing their 

 range — and the Channel would offer no insuperable obstacle to such 

 extension, but, for effective occupation, although the means may be 

 quite natural, the occasion would probably be due to human agency, 

 such as interference with natural flora — thus the introduction of such 

 trees as our common elm, larch, or lime might have afforded the 

 opportunity for the quite natural establishment here of species not 

 included in the original immigration, but the insects, no less than the 

 trees, can hardly be considered as natxralbj British. 



In this sense then, the "British List" appears as some ancient and 

 •even dilapidated document not everywhere quite legible, from which 

 some excisions have been undoubtedly made, but in which interpola- 

 tions are rare and not always authentic. 



Now to this view it may be objected that humanity and all its 

 works are merely part and parcel of the natural order. And this must 

 be admitted. The operations of Homo sapiens equally with those of 

 Fniiiiica sanijuinea are certainly an integral part of the scheme of 

 nature, and, if the influence exerted by one on a Lomechnsa be simply 

 natural, no less natural in its strictest sense must be the influence of 

 the other on the migrations of a FJrnclnts. But from this strictly 

 logical view of the matter we all with one accord depart. In all 

 Philosophy and all Literature, man, civilised or not, is considered as 

 & force outside of, indeed, antithetical to nature, and the natural and 

 artificial orders held as essentially distinct. 



Again it may be urged that, in asking for proof of strictly natural 

 immigration of every species before granting it a certificate as 

 •" British," we are demanding the impossible. That may be so, but 

 the difficulty of recognition in each instance need not obscure for us 

 the validity of the principle. All we can ever hope for is circumstantial 

 ■evidence more or less strong, and any list must be to a great extent 

 provisional. 



But there is another sense in which this term " the British List " may 

 be used, and perhaps more commonly is used. That I nmy call its prac- 

 tical sense. This is the list, frankly empirical in its scope, which we 

 need for the compilation of our manuals and county faunas, the list by 

 whose aid we space out our cabinets, the list which decides whether we 

 are justified in giving ten shillings for an indifterent specimen of an 

 insect of which we can buy " without guaranty of British origin " a 

 perfect example for twopence. 



The need of such a document is obvious ; it is also obvious that it 

 is demanded principally by the accident of our insularity. In the 

 same sense, no such French or German list would be possible, and one 

 wonders how the entomological citizen of Chicago, or Memphis, solves 

 the difficulty. The " U.S.A. list " would pi-obably be more compre- 

 hensive than that of Europe, and exclusive "State Lists" seem 

 impracticable. 



For myself, T think I should feel inclined to admit into this 



