THE HISTORY OP A DISCOVERY. 45 



types of animals, and of tlie conditions of mineraliza- 

 tion of organic remains, possessed by few even of pro- 

 fessional geologists. Thus Eozoon has met with some 

 negative scepticism and a little positive opposition, — 

 though the latter has been small in amount, when we 

 consider the novel and startling character of the facts 

 adduced. 



^^The united thickness,'^ says Sir William Logan, 

 '^p£ these three great series, the Lower and Upper 

 Laurentian and Huronian, may possibly far surpass 

 that of all succeeding rocks, from the base of the Palgeo- 

 zoic to the present time. We are thus carried back 

 to a period so far remote that the appearance of the 

 so-called Primordial fauna may be considered a com- 

 paratively modern event. ^^ So great a revolution of 

 thought, and this based on one fossil, of a character 

 little recognisable by geologists generally, might well 

 tax the faith of a class of men usually regarded as 

 somewhat faithless and sceptical. Yet this new exten- 

 sion of life has been generally received, and has found 

 its way into text-books and popular treatises. Its 

 opponents have been under the necessity of inventing 

 the most strange and incredible pseudomorphoses 

 of mineral substances to account for the facts; and 

 evidently hold out rather in the spirit of adhesion to 

 a lost cause than with any hope of ultimate success. 

 As might have been expected, after the publication of 

 the original paper, other facts developed themselves. 

 Mi*. Yennor found other and scarcely altered speci- 

 mens in the Upper Laurentian or Huronian of Tudor. 



