[Illustration: Fig. 11. _Portion of Eozoon magnified 100 diameters, showing the original Cell-wall with Tubulation, and the Supplemental Skeleton with Canals._ (_After Carpenter._) (_a._) Original tubulated wall or "Nummuline layer," more magnified in fig. 2. (_b, c._) "Intermediate skeleton," with canals.] The immediate result was a composite paper in the _Proceedings of the Geological Society_, by Sir W. E. Logan, Dr. Carpenter, Dr. Hunt, and myself, in which the geology, palæontology, and mineralogy of _Eozoon Canadense_ and its containing rocks were first given to the world.[L] It cannot be wondered at that when geologists and palæontologists were thus required to believe in the existence of organic remains in rocks regarded as altogether Azoic and hopelessly barren of fossils, and to carry back the dawn of life as far before those Primordial rocks, which were supposed to contain its first traces, as these are before the middle period of the earth's life history, some hesitation should be felt. Further, the accurate appreciation of the evidence for such a fossil as Eozoon required an amount of knowledge of minerals, of the more humble types of animals, and of the conditions of mineralization of organic remains, possessed by few even of professional geologists. Thus Eozoon has met with some negative scepticism and a little positive opposition,--though the latter has been small in amount, when we consider the novel and startling character of the facts adduced. [Footnote L: _Journal Geological Society_, February, 1865.]