We cannot here enter into detail concerning the numerous interesting phenomena furnished by the geographical and topographical distribution of organic species, which are all wonderfully explained by the theory of selection and migration. For these I refer to the writings of Darwin,(1) Wallace,(36) and Moritz Wagner,(40) in which the important doctrine of the _limits of distribution_—seas, rivers, and mountains—is excellently discussed and illustrated by numerous examples. Only three other phenomena must be mentioned here on account of their special importance. First, the close relation of forms, that is, the striking “family likeness” existing between the characteristic local forms of every part of the globe, and their extinct fossil ancestors in the same part of the globe; secondly, the no less striking “family likeness” between the inhabitants of island groups and those of the neighbouring continent from which the islands were peopled; lastly and thirdly, the peculiar character presented in general by the flora and fauna of islands taken as a whole. All these chorological facts given by Darwin, Wallace, and Wagner—especially the remarkable phenomena of the limited local fauna and flora, the relations of insular to continental inhabitants, the wide distribution of the so-called “cosmopolitan species,” the close relationship of the local species of the present day with the extinct species of the same limited territory, the demonstrable radiation of every species from a single central point of creation—all these, and all other phenomena furnished to us by the geographical and the topographical distribution of organisms, are explained in a simple and thorough manner by the theory of selection and migration, while without it they are simply incomprehensible. Consequently, in the whole of this series of phenomena we find a new and weighty proof of the truth of the Theory of Descent. [1] The world is perfect save where Man Comes in with his strife. [2] Archebiosis (Bastian), Abiogenesis (Huxley). [3] Alle Glieder bilden sich aus nach ew’gen Gesetzen, Und die seltenste Form bewahrt im Geheimniss das Urbild. Also bestimmt die Gestalt die Lebensweise des Thieres. Und die Weise zu leben, sie wirkt auf alle Gestalten Mächtig zurück. So zeiget sich fest die geordnete Bildung, Welche zum Wechsel sich neigt durch äusserlich wirkende Wesen. [4] “Einstweilen bis den Bau der Welt Philosophie zusammenhält, Erhält sich ihr Getriebe Durch Hunger und durch Liebe.” [5] “Allgemeine Naturgeschichte und Theorie des Himmels.” [6] We must wait for fuller information on the subject of Bathybius, at the hands of the naturalists of the _Challenger_ expedition, before accepting it finally as a distinct organism.—_Editor._ END OF VOL. I. WORKS OF PROFESSOR ERNST HAECKEL.