procuring food, escape from enemies. The continued function of parts of an organism changes the old and produces new organs. The acquirements are inherited by the offspring, and thus are produced the more complicated from simpler organisms. Continued disuse brings about degeneration and ultimate loss of an organ.
Lamarck consequently sees in the adaptability, or power of adaptation, which he assumes for all living matter the ultimate cause of variation; and, as he was certainly the first to point out that acquired characters are inherited by the progeny, he has given a working explanation of Evolution.
But his doctrine did not spread—partly because he was misunderstood. His theory, that a new want, by making itself felt, exacts from the animal new exertions, perhaps from parts hitherto not used, until the want is satisfied—this way of putting it sounds too teleological to explain the yearned-for change in a mechanical or natural way. Moreover,
