"This view, which at once explains the origin of all these bedded rocks, and the fact that their constituent mineral species, like silica and carbonate of lime, replace the perishable matter of organic forms, is designated by Messrs. King and Rowney 'as so completely destitute of the characters of a scientific hypothesis as to be wholly unworthy of consideration,' and they speak of my attempt to maintain this hypothesis as 'a total collapse.' How far this statement is from the truth my readers shall judge. My views as to the origin of serpentine and other silicated minerals were set forth by me as above in 1860-1864, before anything was known of the mineralogy of Eozoon, and were forced upon me by my studies of the older crystalline schists of North America. Naumann had already pointed out the necessity of some such hypothesis when he protested against the extravagances of the pseudomorphist school, and maintained that the beds of various silicates found in the crystalline schists are original deposits, and not formed by an epigenic process (_Geognosie_, ii., 65, 154, and _Bull. Soc. Geol. de France_, 2, xviii., 678). This conclusion of Naumann's I have attempted to explain and support by numerous facts and observations, which have led me to the hypothesis in question. Gümbel, who accepts Naumann's view, sustains my hypothesis of the origin of these rocks in a most emphatic manner,[AY] and Credner, in discussing the genesis of the Eozoic rocks, has most ably defended it.[AZ] So much for my theoretical views so contemptuously denounced by Messrs. King and Rowney, which are nevertheless unhesitatingly adopted by the two geologists of the time who have made the most special studies of the rocks in question,--Gümbel in Germany, and Credner in North America. [Footnote AY: _Proc. Royal Bavarian Acad._ for 1866, translated in _Can. Naturalist_, iii., 81.] [Footnote AZ: _Die Gliederung der Eozoischen Formations gruppe Nord.-Amerikas,--a Thesis defended before the University of Leipzig, March 15, 1869_, by Dr. Hermann Credner. Halle, 1869, p. 53.]