THE HISTORY OP A DISCOVERY. 45 



types of animals, and of the 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, 

 " of 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 Paleo- 

 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. 

 Mr. Vennor found other and scarcely altered speci- 

 mens in the Upper Laurentian or Huronian of Tudor. 



