"16th. In order to account for certain _untoward_ difficulties presented by the configurations forming the 'canal system,' and the aciculi of the 'nummuline layer'--that is, when they occur as '_solid bundles_'--or are '_closely packed_'--or '_appear to be glued together_'--Dr. Carpenter has proposed the theory that the sarcodic extensions which they are presumed to represent have been 'turned into stone' (a 'silicious mineral') 'by Nature's cunning' ('just as the sarcodic layer on the surface of the shell of living Foraminifers is formed by the spreading out of _coalesced_ bundles of the pseudopodia that have emerged from the chamber wall')--'by a process of chemical substitution _before_ their destruction by ordinary decomposition.' We showed this quasi-alchymical theory to be altogether unscientific. "17th. The 'silicious mineral' (serpentine) has been analogued with those forming the variously-formed casts (in 'glauconite,' etc.) of recent and fossil Foraminifers. We have shown that the mineral silicates of Eozoon have no relation whatever to the substances composing such casts. "18th. Dr. Hunt, in order to account for the serpentine, loganite, and malacolite, being the presumed in-filling substances of Eozoon, has conceived the 'novel doctrine,' that such minerals were _directly_ deposited in the ocean waters in which this 'fossil' lived. We have gone over all his evidences and arguments without finding _one_ to be substantiated. "19th. Having investigated the alleged cases of 'chambers' and 'tubes' occurring 'filled with calcite,' and presumed to be 'a conclusive answer to' our 'objections,' we have shown that there are the strongest grounds for removing them from the category of reliable evidences on the side of the organic doctrine. The Tudor specimen has been shown to be equally unavailable. "20th. The occurrence of the best preserved specimens of Eozoon Canadense in rocks that are in a '_highly crystalline condition_' (Dawson) must be accepted as a fact utterly fatal to its organic origin. "21st. The occurrence of 'eozoonal features' _solely_ in crystalline or metamorphosed rocks, belonging to the Laurentian, the Lower Silurian, and the Liassic systems--never in ordinary unaltered deposits of these and the intermediate systems--must be assumed as completely demonstrating their purely mineral origin." The answers already given to these objections may be summed up severally as follows:-- 1st. This is a mere hypothesis to account for the forms presented by serpentine grains and by Eozoon. Hunt has shown that it is untenable chemically, and has completely exploded it in his recent papers on Chemistry and Geology.[AP] My own observations show that it does not accord with the mode of occurrence of serpentine in the Laurentian limestones of Canada. [Footnote AP: Boston, 1874.]