F. To continue then with the cats. Famine comes and tests them, so to
speak; the weaker, the less active, the less cunning, and the less
enduring cats get killed off, and only the strongest and smartest cats
survive; there will be no favouritism shown to animals in a state of
Nature; they will be weighed in the balance, and the weight of a hair
will sometimes decide whether they shall be found wanting or no. This
being the case, the cats having been thus naturally culled and the
stronger having been preserved, there will be a gradual tendency to
improve manifested among the cats, even as among our own mobs of sheep
careful culling tends to improve the flock.