Lamarck on the contrary, inspired all his plants and animals--fungi and frogs, and elephants and apes--with the desire of getting on in the world and improving their limbs by exercise; so the greyhound grew slim and fleet by running; the giraffe's neck elongated by reaching up to the branches of the trees on which it browsed, and the duck acquired web feet by swimming.

Others attributed the evolution of differences to external conditions.

The negro became black by exposure to the tropical sun; the arctic hare received its coat of thick white fur from the cold climate, and the buffalo and camel their humps of fat from the sterility of their pastures at certain seasons, and the consequent need of a reserved store of fat for food for the rest of the body.

Mr.Darwin's doctrine of Natural Selection refuses Lamarck's notion of any conscious attempt of the plant or animal at improvement; and equally denies the power of external nature to improve anything, except by killing off poor specimens, save in that very limited range where good pastures make fat animals for a season or two.

An innate power of accidental variation to a very small amount, and the slow but constant adding up of profitable variations during countless generations, with the killing off of the unimproved breeds by Natural Selection, is his patent populator and improver.