THE SHAPES OF BIRDS 265 
trees. Mr. Oates adds, “they seldom or never descend 
to the ground.” 
This statement is not strictly true. I have repeatedly 
seen the fantail, the grey, and the black and orange 
species on the ground. But the point I desire to em- 
phasise is that their methods of obtaining food are all 
very much the same. Were all the species of the same 
colour and shape, I think few observers would be able 
to distinguish one species from another, merely by 
watching their methods of securing food. Their varied 
nesting habits would, of course, serve to distinguish 
them. 
Here, then, we have five species of birds, living side 
by side, under similar conditions and eating the same 
description of food, obtained by like methods, yet 
arrayed in totally different plumage and of varying 
form. 
Passing over the differences in colouration, let us con- 
fine ourselves to configuration. Why are these birds 
not all of the same shape? They are related to one 
another; all are descendants of a common ancestor, 
and, as we have seen, their methods of obtaining food 
are not marked by any considerable differences ; why, 
then, are they not all of one shape—the shape best 
suited to flycatching birds? 
I do not think for a moment that it is possible 
successfully to maintain that the shape of each par- 
ticular species is so important to it that, were the bird 
of any other shape, it must perish in the struggle for 
existence. The paradise flycatcher disproves such an 
hypothesis, The male and female differ considerably 
