This discovery is also of importance as connecting Eozoon through Cryptozoon with large organisms, probably Protozoa, extending upward to the top of the Cambrian, and thus forming a link of connection between the life of the Eozoic and that of the Palæozoic period. Matthew has also described forms which he regards as spicules of sponges from the Laurentian of New Brunswick.[42] One of these seems to present cruciform needles forming square areas, like the Protospongia of Salter, from the Cambrian. The other has simple elongate needle-like spicules arranged in bundles. Matthew summarizes the rocks containing these fossils as in the table on p, 216, in descending order, the highest bed being below the Etcheminian.[43] The first and second groups, it will be observed, are equivalent to the Huronian; the third corresponds to the Grenvillian, and the fourth to the Lower Laurentian. [Footnote 42: Fuller descriptions of these rocks may be found in _Rep. Prog. Geol. Surv. of Canada_, 1872, pp. 30, 34, etc.] [Footnote 43: _Bulletin Nat. Hist. Society of New Brunswick_, 1890 where further details are given as to the fossils.] _DIFFICULTIES AND OBJECTIONS_ IX _DIFFICULTIES AND OBJECTIONS_ The active objectors to the animal nature of Eozoon have been few, though some of them have returned to the attack with a pertinacity and determination which would lead one to believe that they think the most sacred interests of science to be dependent on the annihilation of this proto-foraminifer. I do not propose here to treat of the objections in detail. I have presented the case of Eozoon on its own merits, and on these it must stand. I may merely state that the objectors strive to account for the existence of Eozoon by purely mineral deposition, and that the complicated changes which they require to suppose are perhaps the strongest indirect evidence for the necessity of regarding the structures as organic. The reader who desires to appreciate this may consult my memoir of 1888.[44] [Footnote 44: Also Rowney and King's papers in _Journal Geological Society_, August, 1866; and _Proceedings Irish Academy_, 1870 and 1871.]