8 
A NATURALIST ON THE PROWL. 
away without knowing why, startled but not frightened. 
A rival passes and it dashes at him, powerless to hurt, but 
bursting with nervous energy which must find an outlet, 
and the two in mock combat mount up into the sky until 
they are lost to sight. When it comes down again rest 
seems sweet, so it sits on a leaf and spreads its wings 
to the life-giving rays of the sun, or it feels a sensation 
which we may call thirst, and the fragrance of a flower, 
answering to that feeling, impels it to unfurl its long tongue 
and sip those sweets which it never sipped before. At 
length some sensations of maternity, transitory but urgent, 
take possession of it, under the influence of which it hovers 
round a tree, the scent of whose leaves recalls vaguely some 
former life “ that had elsewhere its setting,” and to those 
leaves it feels impelled to commit the burden which it 
bears. And now the superabounding energy abates, the 
impulses grow weaker, the thrills of joy become rapidly 
duller, and without pain or regret it flickers out, like a lamp 
when the oil is spent. 
This is not a “ working theory,” but only my way of 
clothing with flesh and blood the dry bones of scanty facts, 
as geologists restore in pictures the giant forms whose 
skeletons they have dug out of the bowels of the earth. 
