84 INSECTS AND THEIR ALLIES. 
power of its abdomen or hind-body, as it swims through — 
its little “world of waters” by jerks. So also the Am- 
phipod, a crab-like being, higher in the scale than the 
_ water flea, darts from weed to weed in the clear cool 
waters of tidal pools, by most gracefully jerking its 
abdominal rings. So also the clumsy crab clambers ~ 
cautiously obliquely backwards over the pebbles by a 
jerking sort of gait; and the lobster carelessly bends its 
tail beneath its breast, and like a flash, lands softly a 
fathom away, in its course leaping the Laminaria swaying 
to and fro in the ebbing tide. 
Compare with these stiff and clumsy motions, the flight 
-of a swallow-tailed Butterfly, as it emulates all the mo- 
tions of an eagle in its majestic flight over forests and 
through sequestered glades. The lowest of butterflies, 
the small dun colored Hesperiadx, or Skippers, jerk as 
they fly. Or compare again the swift, vivacious, inquis- 
itive motions of an Ichneumon fly, just as it has alighted 
upon a leaf. See the intensity of life in every dovanai 
of its open, restless wings ; the head turning this way and 
that, with the vibrating feelers and threadlike waving 
antennæ, prompted by the nervous energy within ;, its 
arching abdomen directing each incessant and swift dart- 
ing movement of its ovipositor, while running from leaf 
to leaf in its anxious search for some unlucky caterpillar 
in which to lay its eggs. In this tiny insect is a special- 
D a Ee: 
