When writing the dedication of this work, I little thought that the eminent geologist and valued friend to whom it gave me so much pleasure to tender this tribute of respect, would have passed away before its publication. But so it is, and we have now to mourn, not only Lyell, who so frankly accepted the evidence in favour of Eozoon, but Logan, who so boldly from the first maintained its true nature as a fossil. This boldness on his part is the more remarkable and impressive, from the extreme caution by which he was characterized, and which induced him to take the most scrupulous pains to verify every new fact before committing himself to it. Though Sir William's early work in the Welsh coal-fields, his organization and management of the Survey of Canada, and his reducing to order for the first time all the widely extended Palæozoic formations of that great country, must always constitute leading elements in his reputation, I think that in nothing does he deserve greater credit than in the skill and genius with which he attacked the difficult problem of the Laurentian rocks, unravelled their intricacies, and ascertained their true nature as sediments, and the leading facts of their arrangement and distribution. The discovery of Eozoon was one of the results of this great work; and it was the firm conviction to which Sir William had attained of the sedimentary character of the rocks, which rendered his mind open to the evidence of these contained fossils, and induced him even to expect the discovery of them. This would not be the proper place to dwell on the general character and work of Sir William Logan, but I cannot close without referring to his untiring industry, his enthusiasm in the investigation of nature, his cheerful and single-hearted disposition, his earnest public spirit and patriotism--qualities which won for him the regard even of those who could little appreciate the details of his work, and which did much to enable him to attain to the success which he achieved. INDEX. Acervuline explained, 66. Acervuline Variety of Eozoon, 135. Aggregative Growth of Animals, 213. Aker Limestone, 197. Amity Limestone, 197. Amœba described, 59. Annelid Burrows, 133, 139. Archæospherinæ, 137, 148. Archæocyathus, 151. Arisaig, Supposed Eozoon of, 140. Bathybius, 65. Bavaria, Eozoon of, 148. Beginning of Life, 215. Billings, Mr.,--referred to, 41; on Archæocyathus, 151; on Receptaculites, 163. Calumet, Eozoon of, 38. Calcarina, 74. Calcite filling Tubes of Eozoon, 98. Canal System of Eozoon, 40, 66, 107, 176, 181. Carpenter--referred to, 41; on Eozoon, 82; Reply to Carter, 204. Caunopora, 158. Chrysotile Veins, 107, 180. Chemistry of Eozoon, 199. Coccoliths, 70. Cœnostroma, 158. Contemporaries of Eozoon, 127. Côte St. Pierre, 20. Derivation applied to Eozoon, 225. Discovery of Eozoon, 35. Eozoic Time, 7.