12th. If this is true of the Aker marble, then it must contain Eozoon; and specimens of the Amity limestone which I have examined, certainly contain large fragments of Eozoon. 13th. The configuration of the canal system is quite definite, though varying in coarseness and fineness. It is not known to occur independently of the forms of Eozoon except in fragmental deposits. 14th. The argument is not that they are "occasionally found together in ophite," but that they are found together in specimens preserved by different minerals, and in such a way as to show that all these minerals have filled chambers, canals, and tubuli, previously existing in a skeleton of limestone. 15th. The lamination of Eozoon is not like that of any rock, but a strictly limited and definite form, comparable with that of Stromatopora. 16th. This I pass over, as a mere captious criticism of modes of expression used by Dr. Carpenter. 17th. Dr. Hunt, whose knowledge of chemical geology should give the greatest weight to his judgment, maintains the deposition of serpentine and loganite to have taken place in a manner similar to that of jollyte and glauconite in undoubted fossils: and this would seem to be a clear deduction from the facts he has stated, and from the chemical character of the substances. My own observations of the mode of occurrence of serpentine in the Eozoon limestones lead me to the same result. 18th. Dr. Hunt's arguments on the subject, as recently presented in his _Papers on Chemistry and Geology_, need only be studied by any candid and competent chemist or mineralogist to lead to a very different conclusion from that of the objectors. 19th. This is a mere statement of opinion. The fact remains that the chambers and canals are sometimes filled with calcite. 20th. That the occurrence of Eozoon in crystalline limestones is "utterly fatal" to its claims to organic origin can be held only by those who are utterly ignorant of the frequency with which organic remains are preserved in highly crystalline limestones of all ages. In addition to other examples mentioned above, I may state that the curious specimen of Cœnostroma from the Guelph limestone figured in Chapter VI., has been converted into a perfectly crystalline dolomite, while its canals and cavities have been filled with calcite, since weathered out. 21st. This limited occurrence is an assumption contrary to facts. It leaves out of account the Tudor specimens, and also the abundant occurrence of the Stromatoporoid successors of Eozoon in the Silurian and Devonian. Further, even if the Eozoon were limited to the Laurentian, this would not be remarkable; and since all the Laurentian rocks known to us are more or less altered, it could not in that case occur in unaltered rocks.