Our science of evolution won its greatest triumph when, at the beginning of the twentieth century, its most powerful opponents, the Churches, became reconciled to it, and endeavoured to bring their dogmas into line with it. A number of timid attempts to do so had been made in the preceding ten years by different free-thinking theologians and philosophers, but without much success. The distinction of accomplishing this in a comprehensive and well-informed manner was reserved for a Jesuit, Father Erich Wasmann of Luxemburg. This able and learned entomologist had already earned some recognition in zoology by a series of admirable observations on the life of ants, and the captives that they always keep in their homes, certain very small insects which have themselves been curiously modified by adaptation to their peculiar environment. He showed that these striking modifications can only be rationally explained by descent from other free-living species of insects. The various papers in which Wasmann gave a thoroughly Darwinian explanation of the biological phenomena first appeared (1901-1903) in the Catholic periodical, _Stimmen aus Maria-Laach_, and are now collected in a special work entitled, _Modern Biology and the Theory of Evolution_. This remarkable book of Wasmann's is a masterpiece of Jesuitical sophistry. It really consists of three entirely different sections. The first third gives, in the introduction, what is, for Catholics, a clear and instructive account of modern biology, especially the cell-theory, and the theory of evolution (chapters i.-viii.). The second third, the ninth chapter, is the most valuable part of the work. It has the title: "The Theory of Fixity or the theory of Evolution?" Here the learned entomologist gives an interesting account of the results of his prolonged studies of the morphology and the œcology of the ants and their captives, the myrmecophilæ. He shows impartially and convincingly that these complicated and remarkable phenomena can only be explained by evolution, and that the older doctrine of the fixity and independent creation of the various species is quite untenable. With a few changes this ninth chapter could figure as a useful part of a work by Darwin or Weismann or some other evolutionist. The succeeding chapter (the last third) is flagrantly inconsistent with the ninth. It deals most absurdly with the application of the theory of evolution to man. The reader has to ask himself whether Wasmann really believes these confused and ridiculous notions, or whether he merely aims at befogging his readers, and so preparing the way for the acceptance of the conventional creed.