Moreover, it is a demonstrable impossibility to explain the origin of just those organs and members in the structure of organisms which are systematically the most significant and functionally the most important, by means of natural selection. It is true that many of these organs and members, in their perfected state, offer to the organism an immense advantage over lower organisms; but if they had been originated through gradual development, they would have been in their first {105} beginnings and earlier stages of development at least quite indifferent, often directly obstructive to the individual in its struggle for existence, and therefore would have been called into existence and developed by agencies which had an effect directly counteracting natural selection. How high, for instance, stand the vertebrates above the invertebrates! Yet how could the first deviation from the ganglionic system of the nerves of the invertebrates to the cerebro-spinal system of the vertebrates have occurred?--and, especially, how could the first deposit of the vertebral column have procured any benefit to the individual in the struggle for existence? We quote this objection from Karl Planck's "Wahrheit und Flachheit des Darwinismus," ("Truth and Platitude of Darwinism"), Noerdlingen, Beck, 1872. Still more striking is the insufficiency of the selection theory for the explanation of the origin of the organs of motion in the higher classes of vertebrates. A. W. Volkman says of it, in his instructive lecture, "Zur Entwickelung der Organismen," ("Development of the Organisms") Halle, Schmidt, 1875, p. 3 ff.: "Without doubt, animals with extremities will come from animals which lacked extremities. Now if the metamorphosis originated in the course of one generation, the animals with extremities would have an advantage over the rest, which ought to show itself in the natural selection; but if the development of an extremity needs 10,000 generations, the individual in which the process of the development begins produces 1/10000 of the extremity and the advantage, resulting therefrom is reduced to zero. For an organ can only be of advantage when it performs its functions; and on {106} the first of the 10,000 stages of development the extremity can not perform its functions. Just think of the cetacea! Of the hind extremity, only its carrier, the pelvis, has been developed; and even this is only represented by the two hip-bones, hanging in the flesh. As to the python, the hind extremities are more complete, but they lie hidden under the skin, and therefore are of no use for local movement. Such examples show that in the history of the development of an organ thousands of years may pass, and numerous generations may arise and disappear, until it reaches that grade of perfection where it is of use to its owner. How therefore, can we look upon such an organ, when finally it is perfect, as a product of selection in the sense of Darwin?"