Chap. x. in lowest Fossiliferous Strata. 287 



Silurian stratum the first dawn of life. Other highly competent 

 judges, as Lyell and E. Forbes, have disputed this conclusion. 

 We should not forget that only a small portion of the world is 

 known with accuracy. Not very long ago M. Barrande added 

 another and lower stage, abounding with new and peculiar species, 

 beneath the then known Silurian system; and now, still lower 

 down in the Lower Cambrian formation, Mr. Hicks has found 

 in South Wales beds rich in trilobites, and containing various 

 molluscs and annelids. The presence of phosphatic nodules and 

 bituminous matter, even in some of the lowest azoic rocks, probably 

 indicates life at these periods ; and the existence of the Eozoon in 

 the Laurentian formation of Canada is generally admitted. There 

 are three great series of strata beneath the Silurian system in 

 Canada, in the lowest of which the Eozoon is found. Sir W. 

 Logan states that their " united thickness may possibly far surpass 

 " that of all the succeeding rocks, from the base of the paleozoic 

 " series to the present time. We are thus carried back to a period 

 " so remote, that the appearance of the so-called Primordial fauna 

 " (of Barrande) may by some be considered as a comparatively 

 " modern event." The Eozoon belongs to the most lowly organised 

 of all classes of animals, but is highly organised for its class ; it 

 existed in countless numbers, and, as Dr. Dawson has remarked, 

 certainly preyed on other minute organic beings, which must have 

 lived in great numbers. Thus the words, which I wrote in 1859, 

 about the existence of living beings long before the Cambrian 

 period, and which are almost the same with those since used by 

 Sir W. Logan, have proved true. Nevertheless, the difficulty of 

 assigning any good reason for the absence of vast piles of strata 

 rich in fossils beneath the Cambrian system is very great. It does 

 not seem probable that the most ancient beds have been quite 

 worn away by denudation, or that their fossils have been wholly 

 obliterated by metamorphic action, for if this had been the case 

 we should have found only small remnants of the formations next 

 succeeding them in age, and these would always have existed in a 

 partially metamorphosed condition. But the descriptions which we 

 possess of the Silurian deposits over immense territories in Bussia 

 and in North America, do not support the view, that the older a 

 formation is, the more invariably it has suffered extreme denudation 

 and metamorphism. 



The case at present must remain inexplicable ; and may be truly 

 urged as a valid argument against the views here entertained. To 

 show that it may hereafter receive some explanation, I will give 

 the following hypothesis. From the nature of the organic remains 



