I. Haeckel and His Opponents

[^9]: Purposeless organs. As to these organs Haeckel observes in his book Die Welträtsel, p. 306: “All higher animals and plants, indeed all those organisms whose bodies are not quite simply built, but are composed of several organs working purposefully together, reveal on attentive examination a number of useless or ineffective, yes, even of dangerous and harmful, arrangements. ... The explanation of these purposeless arrangements is quite simply given by the theory of descent. It shows that these rudimentary organs are atrophied, and that by want of use. ... The blind struggle for existence between the organs conditions just as much their historical destruction, as it originally caused their arising and development.”