116 BOMBAY DUCKS 
come out again, dashed his prey to death on a stone, 
and swallowed the luckless fish. 
The roller obtains his insect quarry in a very similar 
way. He takes up his position on the summit of a post, 
or on a railing, or a telegraph wire, and sits there motion- 
less, pretending to be asleep. Asa matter of fact, he is 
keeping a very sharp look out. Presently he espies an 
insect moving on the ground below, whereupon he flies 
to the ground and returns to his perch with the insect 
inside him. Both kingfishers and rollers must have 
marvellous eyesight. A roller will “spot” an insect in 
the grass twenty or thirty feet away and fly down and 
seize it. 
The white-breasted kingfisher is, as we have seen, an 
example of a bird which is undergoing evolution under 
our very eyes. As generation succeeds generation, this 
bird goes in less for fishing and more for insect catching, 
so that now he often lives and flourishes far away from 
water, feeding almost entirely on insects. Hence his 
habits approximate very closely to those of the roller. 
There is, consequently, nothing wildly improbable in 
the hypothesis that, far back in the dim vista of time, 
there was no distinction between rollers and kingfishers, 
that the ancestral roller-kingfisher was a brilliantly 
coloured bird which picked up a living in a varieiy of 
ways, sometimes catching insects and at others fish, 
those that lived near streams naturally devoting them- 
selves more exclusively to fish catching, and those which 
dwelt on the plains, far from water, contenting them- 
selves with hunting insects, 
Thus two races, having distinct habits, were formed, 
