CI1AP. XVI.] 
THE BRITISH ISLES. 
325 
modified by the particular conditions of the lake in which they 
have found themselves isolated. 
Peculiar British Insects . — We now come to the class of insects, 
and here we have much more difficulty in determining what are 
the actual facts, because new species are still being yearly dis- 
covered and considerable portions of Europe are but imperfectly 
explored. It often happens that an insect is discovered in our 
islands, and for some years Britain is its only recorded locality ; 
but at length it is found on some part of the continent, and not 
unfrequently has been all the time known there, but disguised 
by another name, or by being classed as a variety of some other 
species. This has occurred so often that our best entomologists 
have come to take it for granted that all our supposed peculiar 
British species are really natives of the continent and will one 
day be found there; and owing to this feeling little trouble 
has been taken to bring together the names of such as from 
time to time remain known from this country only. The view of 
the probable identity of our entire insect-fauna with that of the 
continent is held by such well-known authorities as Mr. E. C. Rye 
and Dr. D. Sharp for the beetles, and by Mr. H. T. Stainton 
for butterflies and moths ; but as we have already seen that 
amonsf two orders of vertebrates — birds and fishes — there are 
undoubtedly peculiar British species, it seems to me that all the 
probabilities are in favour of there being a much larger number 
of peculiar species of insects. In every other island where 
some of the vertebrates are peculiar — as in the Azores, the 
Canaries, the Andaman Islands, and Ceylon— the insects show an 
equal if not a higher proportion of speciality, and there seems 
no reason whatever why the same law should not apply to us. 
Our climate is undoubtedly very distinct from that of any part 
of the continent, and in Scotland, Ireland, and Wales we possess 
extensive tracts of wild mountainous country where a moist 
uniform climate, an alpine or northern vegetation, and a con- 
siderable amount of isolation, offer all the conditions requisite 
for the preservation of some species which may have become 
extinct elsewhere, and for the slight modification of others 
since our last separation from the continent. I think, therefore, 
that it will be very interesting to take stock, as it were, of our 
