212 GLAUCUS ; OR, 
too great for one man, so prodigal is Nature of her 
forms, in the stream as in the ocean; but whatif a 
correspondence were opened between a few fishermen 
—of whom one should live, say, by the Hampshire 
or Berkshire chalk streams; another on the slates 
and granites of Devon; another on the limestones 
of Yorkshire or Derbyshire ; another among the yet 
earlier slates of Snowdonia, or some mountain part 
of Wales; and more than one among the hills of 
the Border and the lakes of the Highlands? Each 
would find (I suspect), on comparing his insects with 
those of the others, that he was exploring a little 
pecutiar world of his own, and that with the excep- 
tion of a certain number of typical forms, the flies 
of his county were unknown a hundred miles away, 
or, at least, appeared there under great differences of 
size and colour; and each, if he would take the 
trouble to collect the caddises and water-crickets, 
and breed them into the perfect fly in an aquarium, 
would see marvels in their transformations, their 
instincts, their anatomy, quite as great (though not, 
perhaps. as showy and startling) as I have been 
