or were they not liable in some way to be checked by other causes?
Remember the quail; how plentiful they were until the cats came with
the settlers from Europe. Why were they so abundant? Simply because
they had plenty to eat, and could get sufficient shelter from the
hawks to multiply freely. The cats came, and tussocks stood the poor
little creatures in but poor stead. The cats increased and
multiplied because they had plenty of food and no natural enemy to
check them. Let them wait a year or two, till they have materially
reduced the larks also, as they have long since reduced the quail,
and let them have to depend solely upon occasional dead lambs and
sheep, and they will find a certain rather formidable natural enemy
called Famine rise slowly but inexorably against them and slaughter
them wholesale. The first proposition then to which I demand your
assent is that all plants and animals tend to increase in a high
geometrical ratio; that they all endeavour to get that which is
necessary for their own welfare; that, as unfortunately there are
conflicting interests in Nature, collisions constantly occur between
different animals and plants, whereby the rate of increase of each
species is very materially checked. Do you admit this?

C. Of course; it is obvious.

F. You admit then that there is in Nature a perpetual warfare of
plant, of bird, of beast, of fish, of reptile; that each is striving
selfishly for its own advantage, and will get what it wants if it
can.

C. If what?

F. If it can. How comes it then that sometimes it cannot? Simply