. Relics of primeval life, beginning of life in the dawn of geological time. ids, corals, and shells, havecontributed to the formation of the Laurentian lime-stones. (3) In the hydrous silicate (Loganite) filling thechambers of a large specimen of Eozoon fromBurgess, there are numerous small pieces of foreignmatter; and the silicate itself is laminated, indicat-ing its sedimentary nature. Some of the includedfragments appear to be carbonaceous, others cal-careous ; but no distinct organic structure can bedetected in them. There are, however, in the Logan-ite, many minute silicious grains of a
. Relics of primeval life, beginning of life in the dawn of geological time. ids, corals, and shells, havecontributed to the formation of the Laurentian lime-stones. (3) In the hydrous silicate (Loganite) filling thechambers of a large specimen of Eozoon fromBurgess, there are numerous small pieces of foreignmatter; and the silicate itself is laminated, indicat-ing its sedimentary nature. Some of the includedfragments appear to be carbonaceous, others cal-careous ; but no distinct organic structure can bedetected in them. There are, however, in the Logan-ite, many minute silicious grains of a bright greencolour, resembling greensand concretions ; and the 200 RELICS OF PRIMEVAL LIFE manner In which these are occasionally arranged inlines and groups suggests the supposition that theymay possibly be casts of the interior of minute Fora-miniferal shells. They may, however, be concre-tionary in their origin (Fig. 51). (4) In some of the Laurentian limestones sub-mitted to me by Sir W. E. Logan, and in others fromArnprior on the Ottawa, there are fibres and granules. Fig. 51.—ArchaospherincB frofn Burgess Eozoon, Grains included in Loganite. (Magnified.) of carbonaceous matter which do not conform to thecrystalline structure, and present appearances quitesimilar to those which in more modern limestones re-sult from the decomposition of the algae, etc. Thoughretaining mere traces of organic structure, little doubtwould be entertained as to their vegetable origin ifthey were found in fossiliferous limestones. In lime-stones of Upper Laurentian age, near St. John,New Brunswick, more distinct fibres occur, and CONTEMPORARIES OF EOZOON 201 associated with these beds Matthew has foundwhat seem to be spicules of sponges, some simpleand others hexactinelled like those of Protospongiaof the Cambrian. Though the abundance and wide distribution ofEozoon, and the important part it seems to haveacted in the accumulation of limestone, indicate thatit was one of the most prevalent for
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