78 THE BIRD WATCHER 
irrespective of anything that may be growing upon 
it. Having seen thef?do both, I see no reason why 
I should reject the evidence of my eyesight in the 
one case more than in the other. What interests me 
is that I have several times during this week seen 
the same duck, with her young ones, feeding along 
this one flat part of the coast-line, where it forms a 
beach, whereas all the others that I have seen have 
kept in the neighbourhood of the rocks. Even about 
the shores of this small island it seems as though a 
process of differentiation were going on, and that 
whilst the great majority of the eider-ducks affect a diet 
of shell-fish, and, therefore, haunt the broken, rocky 
parts where it is to be best obtained, some few prefer 
the seaweed growing on the smooth, shallow bottoms, 
which they therefore do not leave, or, at least, more 
frequently resort to. 
A difference of food like this, involving a residence 
in different localities, must lead to change in other 
habits, to which structure would, in time, respond, 
so that, at last, upon Darwinian principles, two differ- 
ent birds would be produced. Thus anywhere and 
everywhere one may see with one’s own eyes—or 
think that one sees, which is just as instructive—the 
early unregarded stages of some important evolu- 
tionary process. 
It is a good thing, I think, thus to exercise one’s 
imagination, and by observing this or that more or less 
slight deviation from the main stream of an animal’s 
habits, to try and picture its remote future descendants. 
