FOOTNOTES:

[1] A good definition of degeneracy is that of A. F. Tredgold, who says: “I venture to define degeneracy as ‘a retrograde condition of the individual resulting from a pathological variation of the germ cell.’” (Smithson. Inst. Rpt. for 1918, p. 548.)

[2] The term mutation had been used long before and in a similar sense by the German palæontologist Waagen, who employed it to designate the variations of a specific type that succeed one another in successive strata, a thing which rarely occurs. (Cf. Waagen’s Die Formenreihe des Ammonites subradiatus, Geognost. paläont. Beitr., Berlin, 1869.)

[3] It may be remarked, in passing, that experimental genetics and mutation furnish no clue to the origin of adaptive characters. The Lamarckian idea alone gives promise in this direction. Orthogenesis leaves unsolved the mystery of preadaptation; yet only orthogenetic systems of evolution can be constructed on the basis of genetical facts. “Mutations and Mendelism,” says Kellogg, “may explain the origin of new species in some measure, but they do not explain adaptation in the slightest degree.” (Atlantic Monthly, April, 1924, pp. 488, 489.) We have seen in the previous chapter that they are impotent to explain in any measure the origin of new species.

[4] Rev. Erich Wasmann, S. J., accepts the evolutionary inference from homology as regards plants and animals. When it comes to man, however, he attempts to draw the line, and argues painstakingly against the assumption of a bestial origin of the human body.

[5] This transitory lymphatic, or tracheal venation appearing in the appendages at the stenogastric stage may not have the particular significance that Father Wasmann assigns. Such venation, even if vestigial and aborted, need not necessarily be a vestige of former wing venation. To demonstrate the validity of the atavistic interpretation, all other possible interpretations would have to be definitively excluded.

[6] Vernon Kellogg has expressed this same view in a recent article, though he frankly admits that it is an as yet unrealized desideratum. “Altogether,” he says, “it must be fairly confessed that evolutionists would welcome the discovery of the actual possibility and the mechanism of transferring into the heredity of organisms such adaptive changes as can be acquired by individuals in their lifetime. It would give them an explanation of evolution, especially of adaptation, much more satisfactory than any other explanation at present claiming the acceptance of biologists.” (Atlantic Monthly, April, 1924, p. 488.)

[7] See Addenda.

[8] “It is a common occurrence,” says Charles Schuchert, “on the Canadian Shield to find the Archæozoic formations overlain by the most recent Pleistocene glacial deposits, and even these may be absent. It appears as if in such places no rocks had been deposited, either by the sea or by the forces of the land, since Archæozoic time, and yet geologists know that the shield has been variously covered by sheets of sediments formed at sundry times in the Proterozoic, Palæozoic, and, to a more limited extent, in the Mesozoic.” (“Textbook of Geology,” ed. of 1920, II, p. 569.) It may be remarked that, when geologists “know” such things, they know them in spite of the facts!