getting rid of thousands
more.

The subject of this astonishing increase from a single plant thus became
a topic for subsequent conversation and research. It being in Fred's
line, he looked up several articles about weeds, undertook to extend the
calculation, and arrived at results that almost frightened me. A single
thistle would produce twenty-four thousand the first year, and five
hundred and seventy-six millions the second! and we found that botanists
had discovered in all other weeds an approximation to the same amazing
power of reproduction. It must not be supposed, however, that every seed
will vegetate. Animals and birds consume myriads of them, and other
myriads perish under the extreme heat of summer and the equally
destructive cold of winter. To some extent Nature thus confines the
multiplication of weeds within limits. Botanists assert that these
limits are prescribed, and that they cannot be passed. If it were not
so, the seed of a single thistle would reproduce itself so rapidly as in
a few years to cover with its progeny the entire surface of our planet.

Our ground was singularly troubled with the rag-weed, which we found was
immensely prolific. There were numerous other kinds also that came up
all over the field, and it appeared to me that those which produced the
most seeds threw up the rankest growth. What was greatly to their
discredit, none of them produced a flower. So far as I could discover,
they performed no other office than that of perfecting a crop of seeds
for the sole purpose of next year producing another that would be many
thousand times larger. Their stalks and foliage were rejected by cattle,
and never came to much as fertilizers. It is probable they have some
medicinal virtues, however, as the herb-doctors use them pretty freely.
But I could regard them in no other light than nuisances in a
strawberry-bed.

So universally are weeds regarded as injurious to agriculture, that laws
have been enacted to insure their destruction. In this country it has
been made a finable offence to permit the Canada thistle to perfect its
seeds. France imposes a heavy penalty on all who are in like manner
neglectful of the common thistle. Every man in Denmark who fails to
destroy the corn-marigold is severely punished. In the early history of
Scotland, whoever "poisoned the king's lands with weeds, introducing
thereby a host of enemies," was denounced as a traitor. Unhappily, with
us there has been an a