348 THE CANADIAN NATURALIST. [Oct, 



yet in these our British fundamental rocks, though they are truly 

 of Laurentian age. For although it was supposed for a moment 

 that the rocks of the Connemara district in the west of Ireland 

 were also of that high antiquity, because it was said that they 

 contained an Eozoon, I assert, from my own examination*, as- 

 well as from information obtained during a recent visit by 

 Professor Harkness, that the quartzose, gneissose, and calcareo- 

 serpentinous strata of the Bins of Connemara, in which the sup- 

 posed Eozoon was said to exist, are simply metamorphosed Lower 

 Silurian strata. Professor Harkness will explain this point to you, 

 and will further, I believe, endeavor to convince you that there is 

 no organic structure whatever in the serpentinous rock of Conne- 

 mara. But, whatever may be the decision of microscopists, I 

 must, as a geologist, declare that, inasmuch as zoophytes of a low 

 order (Foraminifera) unquestionably occur in Laurentian rocks, 

 so it. was by no means improbable that the same group of low 

 animals, having, as far as we can detect, no antagonistic contem- 

 poraries, and having been, therefore, free from any " struggle for 

 existence," might have continued to be the inhabitants of sea 

 shores and cliffs during the long succeeding epoch. 



The mere presence of an Eozoon is therefore no proof whatever 

 that the rock in which it occurred is of the " Fundamental " or 

 "Laurentian " age, that point being only capable of settlement by 

 a clear infraposition of the rocks to well-known and clearly defined 

 Lower Palaeozoic deposits, in the lowest of which, or the Cam- 

 brian of the Geological Survey, another form of low zoophyte, and 

 a few worm-tracks have, as yet, alone been detected. 



In a word, this discovery of a foraminifer in the very lowest 

 known deposit, instead of interfering with, sustains the truth of 

 that doctrine which all my experience as a geologist has confirmed, 

 that the lowest animals alone occur in the earliest zone of life, and 

 that this beginning was followed through long periods by crea- 

 tions of higher and higher animals successively. Thus through 

 the whole of the vastly long Lower Silurian period, so rich in all 

 the lower classes of marine animals, whether mollusks, crusta- 

 ceans, or zoophytes, no one has yet detected a vertebrated crea- 

 ture. Fishes first begin to appear in the latest Silurian deposit, 

 from which time to the present day they have never ceased to pre- 

 vail ; and new forms of Vertebrata, adapted to each succeeding 



* See < Siluria,' p. 190. 



