The Laurentian Group is as complex in its composition as the younger fossiliferous metamorphic rocks; silica, alumina, lime, and carbon compose its beds, together with phosphorus, fluor, barytes, &c.; and it develops the same accidental minerals—staurotide, garnet, pyroxenx, metallic compounds, &c. Why then should there not be in it the buried forms of life? It is found that, as we descend in the great sedimentary column, the organic remains gradually lose substance and form, until they wholly disappear, so that in the group with which we are now concerned (the very earliest we know of) not only has the original substance of the animal and its habitation vanished, but, for the most part, the very form also: and we have the residuary elements of the organisms—lime, phosphorous, &c., in masses sometimes extraordinarily large, corresponding with the extent and thickness of this great group, at least 30,000 feet in Canada (Logan), and 30,000 feet in Norway (Durocher).