WAYS OF NATURE 
and fluttering motion of its tail and wings precisely 
as if taking a real instead of an imaginary bath. 
Attempt to thwart the nesting-instinct in a bird 
and see how persistent it is, and how blind! One 
spring a pair of English sparrows tried to build a 
nest on the plate that upholds the roof of my porch. 
They were apparently attracted by an opening about 
an inch wide in the top of the plate, that ran the 
whole length of it. The pair were busy nearly the 
whole month of April in carrying nesting-material 
to various points on that plate. That big crack or 
opening which was not large enough to admit their 
bodies seemed to have a powerful fascination for 
them. They carried straws and weed stalks and 
filled up one portion of it, and then another and 
another, till the crack was packed with rubbish from 
one end of the porch to the other, and the indignant 
broom of the housekeeper grew tired of sweeping 
up the litter. The birds could not effect an entrance 
into the interior of the plate, but they could thrust 
in their nesting-material, and so they persisted week 
after week, stimulated by the presence of a cavity 
beyond their reach. The case is a good illustration 
of the blind working of instinct. 
Animals have keen perceptions, — keener in many 
respects than our own, — but they form no concep- 
tions, have no powers of comparing one thing with 
another. They live entirely in and through their 
senses. 
160 
