the wish to protract indefinitely an imaginary process, which must end at last in an insuperable difficulty. Were Evolutionists content to require a reasonable time for the development of life, and to assign this to an adequate cause, they might see in the reduction of living things in the pre-Cambrian ages to few and generalized or synthetic types, evidence of an actual approach to the beginnings of life, and beyond this to a condition of the earth in which life would be impossible. * * * * * G. Controversies Respecting Eozoon. In the text (Chapter IX.) I have referred in a cursory manner to these, but have felt that it would be unprofitable to fight the old battles over again, except in so far as the objections raised have suggested new lines of study and investigation. The old objections of Messrs. Rowney, King and Carter were conclusively replied to by the late Dr. Carpenter. The later criticisms of Möbius in his elaborated memoir in "Palæontographica" were in appearance more formidable; but he had evidently entered on the question with imperfect material, and a very defective conception of its extent and meaning. His treatment of it was also marked by unfairness to those who had previously worked at the subject, and by that narrow specialism and captious spirit for which German naturalists are too deservedly celebrated. The difficulties he raised were met at the time, more especially in articles by the present writer in the American _Journal of Science_, and in the Canadian Naturalist. Möbius, I have no doubt, did his best from his special and limited point of view; but it was a crime which science should not readily pardon or forget, on the part of editors of the German periodical, to publish and illustrate as scientific material a paper which was so very far from being either fair or adequate. The later objections of Gregory and Lavis are open to similar criticism as imperfect and partial, and as confounding Eozoon with mineral structures which previous writers had carefully distinguished from it. I have stated these points in letters to _Nature_ and to the Council of the Dublin Academy, and have also re-stated the evidence bearing on the animal nature of Eozoon in a series of papers in the Geological Magazine for 1895. I may add here, as apposite to the present condition of the matter, a few remarks referring to the appearance of Eozoon in Dr. Dallinger's new edition of Carpenter's great work on the Microscope,[59] and more especially to his retaining unchanged the description of _Eozoon Canadense_, as a monument of an important research up to a certain date, while adding a note with reference to the later criticisms of Mr. Gregory. [Footnote 59: _Nature_, March 17, 1892.]