Fleischmann further asserts that Haeckel’s “fundamental biogenetic law” has utterly collapsed. “Recapitulation” does not occur. Selenka’s figures of ovum-segmentation show that there are specific differences in the individual groups. The origin and development of the blastoderm or germinal disc has nothing to do with recapitulation of the phylogeny. It is not the case that the embryos of higher vertebrates are indistinguishable from one another. Even the egg-cell has a specific character, and is totally different from any unicellular organism at the Protistan level. The much-cited “gill-clefts” of higher vertebrates in the embryonic stage are not persistent reminiscences of earlier lower stages; they are rudiments or primordia shared by all vertebrates, and developing differently at the different levels; (thus in fishes they become breathing organs, and in the higher vertebrates they become in part associated with the organs of hearing, or in part disappear again). Though Fleischmann’s vigorous protest against over-hastiness in construction and over-confidence on the part of the adherents of the doctrine of descent is very interesting, and may often be justified in detail, it is difficult to resist the impression that the wheat has been rejected with the chaff.(23) Even a layman may raise the following objections: Admitting that the great groups of forms cannot be traced back to one another, the palæontological record still proves, though it may be only in general outline, that within each phylum there has been a gradual succession and ascent of forms. How is the origin of what is new to be accounted for? Without doing violence to our thinking, without a sort of intellectual autonomy, we cannot rest content with the mere fact that new elements occur. So, in spite of all “difficulties,” the assumption of _an actual descent_ quietly forces itself upon us as the only satisfactory clue. And the fact, which Fleischmann does not discuss, that even at present we may observe the establishment of what are at least new breeds, impels us to accept an analogous origin of new species. Even if the biogenetic law really “finds its chief confirmation in its exceptions,” even if we cannot speak of a strict recapitulation of earlier stages of evolution, there are indisputable facts which are most readily interpreted as reminiscences, as due to affiliation (ideal or hereditary), with ancestral forms. (Note, for instance, Weismann’s “prediction,” &c.(24)) Even if Archæopteryx and other intermediate forms cannot be regarded as connecting links in the strict sense, _i.e._, as being stages in the actual pedigree, yet the occurrence of reptilian and avian peculiarities side by side in one organism, goes far to prove the close relationship of the two classes.