XIII INSTINCT AND REASON 335 
tional Crow once made its nest of soda-water bottle 
wires, which it picked up in a backyard. In districts 
liable to floods, Moorhens often build in trees. In 
New Zealand the “Paradise Ducks,’ which usually 
build on the ground near rivers, have been known 
when disturbed to build on the tops of high trees, and 
to bring down their young on their backs to the water. 
But all this does not show that birds have not an 
instinctive knowledge how to build. It only shows 
that their instinct can be modified by reason and 
experience, 
Many nests are works of very great skill. In Eng- 
land we have the Long-tailed Tit’s nest, wonderful for 
its neatness and its beauty. Some of the commonest 
nests, such as the Chaffinch’s, are works of art. The 
Magpie’s, if not beautiful, is a formidable fortress. 
Among foreign birds there are marvellous builders, 
such as the Tailor, Weaver, and Oven birds. For 
fine architecture the feet must have a power of grasp. 
No web-footed bird builds a really clever nest. But 
a long fine beak is not, as Dr. Wallace maintains, 
necessary. Of the four commonest Tits, the Long- 
tailed is by far the best builder, and his beak is 
remarkably short, much shorter than that of the 
other three. The Chaffinch, too, has a short bill and 
makes a good nest. Some birds—e.g., Ducks—have 
beaks that could never turn out very good work ; but, 
speaking generally, skill is more important than a 
beak of a particular form. And to say that a bird 
learns how to build a nest from the casual sight of 
another pair at work is almost as much as to say that 
she already knows how to do it. The power must 
