Bearing in mind these general points of material form and appearance, we may now proceed to inquire as to the following points: (1) _The structures visible in the specimens_; (2) _The manner in which they are represented by different mineral substances, and how these are to be accounted for_; (3) _The explanation of the whole on the supposition that we are dealing with an animal fossil_. (1) In regard to the first of these questions, I may quote here, with some slight alteration, from a recent memoir of my own[29]:-- [Footnote 29: _London Geological Magazine_, 1895.] In recent years I have been disposed to attach more importance than formerly to the general form of Eozoon. The earlier examples studied were, for the most part, imbedded in the limestone in such a manner as to give little definite information as to external form; and at a later date, when Sir William Logan employed one of his assistants, Mr. Lowe, to quarry large specimens at Grenville and Côte St. Pierre, the attempt was made to secure the most massive blocks possible, in order to provide large slabs for showy museum specimens. [Illustration: Fig. 33.--_Weathered surface of Eozoon._ Showing sections of two funnels or tubes with limiting walls, Côte St. Pierre.] More recently, when collections have been made from the eroded and crumbling surfaces of the limestone in its wider exposures, it was found that specimens of moderate size had been weathered out, and could, either naturally or by treatment with acid, be entirely separated from the matrix. Such specimens sometimes showed, either on the surfaces or on the sides of "funnels" and tubes penetrating the mass (Figs. 33, 34), a confluence of the laminæ, constituting a porous cortex or limiting structure. Specimens of this kind were figured in 1888, and I was enabled to add to the characters of the species that the original and proper form was "broadly turbinate with a depression or cavity above, and occasionally with oscula or pits penetrating the mass." The great flattened masses thus seemed to represent confluent or overgrown individuals, often contorted by the folding of the enclosing beds. [Illustration: Fig. 34.--_Section of the Base of a specimen of Eozoon._] This specimen shows an oscuilform, cylindrical funnel, cut in such a manner as to show its _reticulated wall_ and the descent of the laminæ toward it. Two-thirds of natural size. From a photograph. Col. Carpenter, also in Redpath Museum. [This illustration (from Prof. Prestwich's "Geology," vol. ii. p. 21) has been courteously lent by the Clarendon Press, Oxford.]