We little suspect how the woods and wayside places swarm with life. We
see little of it unless we watch and wait. The wild creatures are
cautious about revealing themselves: their enemies are on the lookout
for them. Certain woods at night are alive with flying squirrels which,
except for some accident, we never see by day. Then there are the night
prowlers--skunks, foxes, coons, minks, and owls--yes, and mice.
The wild mice we rarely see. The little shrew mole, which I know is
active at night, I have never seen but once. I once set a trap, called
the delusion trap, in the woods by some rocks where I had no reason to
suspect there were more mice than elsewhere, and two mornings later it
was literally packed full of mice, half a dozen or more.
Turn over a stone in the fields and behold the consternation among the
small folk beneath it,--ants, slugs, bugs, worms, spiders,--all
objecting to the full light of day, not because their deeds are evil,
but because the instinct of self-preservation prompts this course. As I
write these sentences, a chipmunk, who has his den in the bank by the
roadside near by, is very busy storing up some half-ripe currants which
grew on a bush a few yards away. Of course the currants will ferment and
rot, but that consideration does not disturb him; the seeds will keep,
and they are what he is after. In the early summer, before any of the
nuts and grains are ripened, the high cost of living among the lesser
rodents is very great, and they resort to all sorts of makeshifts.
V
In regard to this fullness of life in the hidden places of nature,
Darwin says as much of the world as a whole:
Well may we affirm that every part of the world is
inhabitable. Whether lakes of brine or those subterranean
ones hidden beneath volcanic mountains--warm mineral
springs--the wide expanse and depth of the ocean, the
upper regions of the atmosphere, and even the surface of
perpetual snow--all support organic beings.
Never before was there such a lover of natural history as Darwin. In the
earth, in the air, in the water, in the rocks, in the sand, in the
mud--he scanned the great biological record of the globe as it was never
scanned before. During the voyage of the Beagle he shirked no hardships
to add to his stores of natural knowledge. He would leave the
comfortable ship while it was making its surveys, and make journeys of
hundreds of miles on horseback through rough and dangerous regions to
glean new facts. Grass and water for his mules, and geology or botany or
zoölogy or anthropology for himself, and he was happy. At a great
altitude in the Andes the people had shortness of breath which they
called "puna," and they ate onions to correct it. Darwin says, with a
twinkle in his eye, "For my part I found nothing so good as the fossil
shells."
His Beagle voyage is a regular magazine of natural-history knowledge.
Was any country ever before so searched and sifted for its biological
facts? In lakes and rivers, in swamps, in woods, everywhere his
insatiable eye penetrated. One re-reads him always with a different
purpose in view. If you happen to be interested in insects, you read him
for that; if in birds, you read him for that; if in mammals, in fossils,
in reptiles, in volcanoes, in anthropology, you read him with each of
these subjects in mind. I recently had in mind the problem of the
soaring condor, and I re-read him for that, and, sure enough, he had
studied and mastered that subject, too. If you are interested in seeing
how the biological characteristics of the two continents, North and
South America, agree or contrast with each other, you will find what
you wish to know. You will learn that in South America the
lightning-bugs and glowworms of many kinds are the same as in North
America; that the beetle, or elator, when placed upon its back, snaps
itself up in the air and falls upon its feet, as our species does; that
the obscene fungus, or _Phallus_, taints the tropical forests, as a
similar species at times taints our dooryards and pasture-borders; and
that the mud-dauber wasps stuff their clay cells with half-dead spiders
for their young, just as in North America. Of course there are new
species of animal and plant life, but not many. The influence of
environment in modifying species is constantly in his mind.