Additional Note VII.]

"Each pregnant Oak ten thousand acorns forms
Profusely scatter'd by autumnal storms;
Ten thousand seeds each pregnant poppy sheds
Profusely scatter'd from its waving heads; 350
The countless Aphides, prolific tribe,
With greedy trunks the honey'd sap imbibe;
Swarm on each leaf with eggs or embryons big,
And pendent nations tenant every twig.
Amorous with double sex, the snail and worm,
Scoop'd in the soil, their cradling caverns form;
Heap their white eggs, secure from frost and floods,
And crowd their nurseries with uncounted broods.
Ere yet with wavy tail the tadpole swims,
Breathes with new lungs, or tries his nascent limbs; 360
Her countless shoals the amphibious frog forsakes,
And living islands float upon the lakes.
The migrant herring steers her myriad bands
From seas of ice to visit warmer strands;
Unfathom'd depths and climes unknown explores,
And covers with her spawn unmeasured shores.
--All these, increasing by successive birth,
Would each o'erpeople ocean, air, and earth.

[Footnote: _Ten thousand seeds_, l. 349. The fertility of
plants in respect to seeds is often remarkable; from one root
in one summer the seeds of zea, maize, amount to 2000; of
inula, elecampane, to 3000; of helianthus, sunflower, to
4000; of papaver, poppy, 32000; of nicotiana, tobacco, to
40320; to this must be added the perennial roots, and the
buds. Buds, which are so many herbs, in one tree, the trunk
of which does not exceed a span in thickness, frequently
amount to 10000; Lin. Phil. Bot. p. 86.]

[Footnote: _The countless Aphides_, l. 351. The aphises,
pucerons, or vine-fretters, are hatched from an egg in the
early spring, and are all called females, as they produce a
living offspring about once in a fortnight to the ninth
generation, which are also all of them females; then males
are also produced, and by their intercourse the females
become oviparous, and deposite their eggs on the branches, or
in the bark to be hatched in the ensuing spring.

This double mode of reproduction, so exactly resembling the
buds and seeds of trees, accounts for the wonderful increase
of this insect, which, according to Dr. Richardson, consists
of ten