OPPONENTS AND OBJECTIONS. 205 



dian Ophite, and of still more marked evidences of the same 

 action in other Ophites, has been simply because these argu- 

 ments appeared to me, as I thought they must also appear to 

 others, entirely destitute of logical force. Every scientific 

 palaeontologist I have ever been acquainted with has taken the 

 best preserved specimens, not the worst, as the basis of his 

 reconstructions ; and if he should meet with distinct evidence 

 of characteristic organic structure in even a very small frag- 

 ment of a doubtful form, he would consider the organic origin 

 of that form to be thereby substantiated, whatever might be 

 the evidence of purely mineral arrangement which the greater 

 part of his specimen may present, since he would regard 

 that arrangement as a probable result- of subsequent mineral- 

 ization, by which the original organic structure has been more 

 or less obscured. If this is not to be our rule of interpreta- 

 tion, a large part of the palaeontological work of our time must 

 be thrown aside as worthless. If, for example, Professors 

 King and Eowney were to begin their study of Nummulites by 

 the examination of their most mineralized forms, they would 

 deem themselves justified (according to their canons of inter- 

 pretation) in denying the existence of the tubulation and 

 canalization which I described (in 1849) in the K laevigata pre- 

 served almost unaltered in the London Clay of Bracklesham 

 Bay. 



" My own notions of Eozoic structure have been formed on the 

 examination of the Canadian specimens selected by the experi- 

 enced discrimination of Sir William Logan, as those in which 

 there was least appearance of metamorphism ; and having 

 found in these what I regarded as unmistakable evidence of an 

 organic structure conformable to the f oramin iferal type, I 

 cannot regard it as any disproof of that conformity, either to 

 show that the true Eozoic structure has been frequently 

 altered by mineral metamorphism, or to adduce the occurrence 

 of Ophites more or less resembling the Eozoon of the Canadian 

 Laurentians at various subsequent geological epochs. The 

 existence of any number or variety of purely mineral Ophites 

 would not disprove the organic origin of the Canadian Eozoon 

 unless it could be shown that some wonderful process of 



