RfeUM^ AND GENEUAL DISCUSSION, 



535 



"The fabric seema to have consisted of anperposcd layers, of calcareong shell 



substance, whose continuity is frc(]^uently interrupted The state of 



preservation of the fossil thus corresponds exactly with that of the Silurian 



Stromatopora, to which, indeed, it bears a strong general resemblance 



The shelly layers are as distinct in character from the calcite contents of the 

 chambers, as arc those of the Numniulites of the pyramid-limestone with 

 which they agree in their remarkable hardness, corresponding with that of 

 porcellanous shell. Altogether I have no hesitation iu concurring with Prof. 

 H, A. Nicholson, Prof. G-eikie, and Mr. EtheridgQ in affirming it to be so 

 unmistalcably organic, that, if it be claimed by mineralogists as a 'rock struc- 

 ture,' a large number of universally-accepted fossils will have to go along with 

 it. As it is essentially calcareous in its composition, there is no room for the 

 hypothesis of its production by the process of * mineral segregation/ which is 

 maintained by certain mineralogists .... to have been ade<;[uate to the pro- 

 duction of the alternating layers of serpentine and calcareous shell-substance 

 in- the Canadian Eozoon. And though mineralogical analysis might not im- 

 probably detect small particles of various minerals in its suljstance, their pres- 

 ence no more establishes its claim to be regarded as a mere rock structure, 

 than does the presence of siliceous lilms , ... in a piece of coral-limestone." * 



^ 



Some wceka later Dr. Carpenter acknowledged that the fossil tlma 

 elaborately described by liim was not calcareous^ but that it consisted 

 "of alternating layers of feldspar and quartz — the former simulating 

 an organic structure like that of Stromatopora, and the latter occupying 

 what had been supposed to be the cavities of that structure — together 

 constit atmg what is known to petrologists as * graphic granite.' " f 



In this case, however. Dr. Carpenter might claim that, having made 

 a mistake, he was ready and willing to withdraw his statements after he 

 had been shown to be in error; and that, having done this, the value of 

 his testimony in regard to the Eozoon was not thereby impaired. As 

 an offset to this, we will proceed to show that in the case of one of the 

 fundamentally important features of his supposed Foramiuifor he was 

 also as much mistaken as he was in regard to the graphic granite, and 

 that he has admitted himself to be so; but that he did not make this 

 admission untd after having persisted in his error for many years, so 

 that we are loft entirely in the dark as to how long we must wait before 

 being able to find out what his final opinion will be in a matter of this kind. 

 The point is this : Dr. Carpenter, after having, at various times during 

 an interval of fifteen years, called attention to the so-called "proper 

 wall" or "nummulino layer" of the Eozoon, the existence of which he 

 said that he had been able ^'most saiisfactorUy to determine^' and which 

 he considered to be ^^ a point of the Highest importance in the determina- 



t 



* Nature, 1876, XIV. 9. 



t Ibid., 68. 



