III.—Review of the Evidence for the Animal Nature of Eozoön Canadense

Extract

In recent years I have been disposed to attach more importance than formerly to the general form and macroscopical characters of Eozoön. 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 showing museum specimens. 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 cavities and tubes penetrating the mass, 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.