The first thing to remark [says M. de Quatrefages][311] is that not one of the creatures exhibited in this pedigree has ever been seen, either living or fossil. Their existence is based entirely upon theory.[312] All species, existing or extinct, are said to have been preceded by ancestral forms, which have disappeared leaving no vestige behind.... All the ancestral groups more or less ill represented in the actual organic world, do not suffice to fill up the gaps in his pedigree; from one stage to another there is sometimes too broad a gulf. Then Haeckel invents the types themselves, as well as the line of descent to which he assigns them [for example No. 7, The _Scolecida_, and No. 21, _Pithecanthropus_]. This kind of "Science" does not deserve to be treated seriously. It will be sufficient to cite another observation of M. de Quatrefages:[313] If Darwin erred in regarding our very ignorance as to some degree telling in favour of his notions, he never tried to re-write the missing volumes of the earth's history, to restore the chapters which have been torn out, or to fill the blanks upon pages that have come down to us. But this is just what Haeckel does continually. Whenever a branch or a twig is lacking on his genealogical trees, whenever the transit from one type to another would appear too abrupt, were we to restrict ourselves to creatures actually known, he invents species and groups bodily, to which he unhesitatingly assigns a place in phylogeny, often a part in phylogenesis. Sometimes he calls in ontogeny to countenance the discovery of supposed ancestors: but frequently he does no more than affirm their existence. He thus creates a fauna, entirely hypothetical, of which Vogt rightly said that no man ever saw a trace of it, or ever will. It is in this fashion that Professor Haeckel habitually solves the Riddles of the Universe. As Vogt himself wrote,[314] "We shall be compelled to patch and alter these genealogical trees of species, which up to this time have been set forth as the last word of Science, and especially of Darwinism." And Du Bois-Reymond,[315] "Man's pedigree, as drawn up by Haeckel, is worth about as much as is that of Homer's heroes for critical historians." There remains to be considered Darwin's own explanation of the admitted deficiency of palæontological evidence.