The result has been that this so-called law has fallen into general disrepute among scientists, especially as a means of reconstructing the phylogeny of modern organisms. It is recognized, of course, that comparative embryology can furnish embryological homologies analogous to the homologies of comparative anatomy, but it is now generally acknowledged that the view, which regards the embryological process as an abridged repetition of the various states through which the species has passed in its evolutionary career must be definitively abandoned, and that, as a general law of organic development, the biogenetic principle has been thoroughly discredited. “This law,” says Karl Vogt of Geneva, “which I long held as well-founded, is absolutely and radically false. Attentive study of embryology shows us, in fact, that embryos have their own conditions suitable to themselves, and very different from those of adults.” (Quoted by Quatrefages De Breau, in his “Les Emules de Darwin,” vol. II, p. 13.) “There can no longer be question,” says Prof. M. Caullery of the Sorbonne, “of systematically regarding individual development as a repetition of the history of the stock. This conclusion results from the very progress made under the inspiration received from this imaginary law, the law of biogenesis.” (Smithson. Inst. Rpt. for 1916, p. 325.) This collapse of the biogenetic law has tumbled into ruins the elaborate superstructure of genealogy which Haeckel had reared upon it. His series of thirty stages extending from the fictitious “cytodes” up to man, inclusively, is even more worthless today than it was when Du Bois-Reymond made his ironic comment: “Man’s pedigree, as drawn up by Haeckel, is worth about as much as is that of Homer’s heroes for critical historians.” (_Revue Scientifique_, 1877, I, p. 1101.) Haeckel tried in vain to save his discredited law by means of the expedient of _cænogenesis_, that is, “the falsification of the ancestral record (palingenesis).” That Nature should be guilty of “falsification” is an hypothesis not to be lightly entertained, and it is more credible, as Wasmann remarks, to assume that Haeckel, and not Nature, is the real falsifier, inasmuch as he has misrepresented Nature in his “fundamental biogenetic law.” Cænogenesis is a very convenient device. One can alternate at will between _cænogenesis_ and _palingenesis_, just as, in comparative anatomy, one can alternate capriciously between _convergence_ and _homology_, on the general understanding of its being a case of: “Heads, I win; tails, you lose”—certainly, there is no _objective_ consideration to restrain us in such procedure. “Such weapons as Cænogenesis and Convergence,” says Kohlbrugge (in his “Die Morphologische Abstammung des Menschen,” 1908) “are unfortunately so shaped that anyone can use them when they suit him, or throw them aside when they do not. They show, therefore, in the prettiest way the