396 On the Subject of ^^ ^ozoo^y 



Loganite, and malacolite being the presumed in-filling sub- 

 stances of '•'■ Eozoon^"^ has propounded the "novel doctrine" 

 that such minerals were directly deposited in the ocean- waters 

 in which this " fossil " lived. We have gone over aU his evi- 

 dences and arguments without finding one to be substantiated. 



19th. Having investigated the alleged cases of " cham- 

 bers " and " tubes " occurring " filled with calcite," and pre- 

 sumed to be " a conclusive answer to " our " objections," we 

 have shown that there are the sti-ongest grounds for remo- 

 ving them from the category of reliable evidences on the 

 side of the organic doctrine*. The Tudor specimen has been 

 shown to be equally unavailable. 



20th. The occurrence of the best-preserved specimens of 

 ^^Eozoon canadense''^ in rocks that are in a " J^ighly crystalline 

 condition " (Dawson) must be accepted as a fact utterly fatal 

 to its organic origin f. 



21st. The occurrence of " eozoonal features " solely in 

 crystalline or metamorphosed rocks belonging to the Lauren- 

 tian, the Lower Silurian, and the Liassic systems | (never 

 in ordinary unaltered deposits of these and the intermediate 

 systems) must be assumed as completely demonstrating their 

 purely mineral origin. 



It is understood that a communication from Mr. Arthur 

 Barker will appear, showing that, whatever opinion the late 

 Professor Schultze might hold in the autumn of last year 

 respecting '"'■Eozoon^'' he subsequently changed it after reading 

 our papers. As he expressed a wish to become fully acquainted 

 with the " canal system," we were careful in sending him some 

 instructive specimens exhibiting it in various stages of forma- 

 tion. 



* Proceedings of the Royal Irish Academy, vol. x. pp. 532, 548 ; ihid. 

 new ser. vol. i. p. 10. Dr. Carpenter (also Dr. Dawson) still adduces 

 these unreliable cases, and ignores altogether the grounds on which we 

 have considered them such. 



t Dr. Carpenter, replying to the objection, as put by Mr. T. Mellard 

 Reade, F.G.S., that " Eozoon " only occurs in metamorphosed rocks 

 (' Nature,' No. 60), asserts that its "calcareous lamellae" ("intermediate 

 skeleton ") " show less departure from the shelly texture than do the 

 great majority of undoubted shells, corals, &c. contained in the least- 

 altered rocks of any geological period" ('Nature,' No. 62) — forgetting 

 that as the substance of such fossils has undergone so much change, 

 the fact demands a vast amount of metamorphism to convert the rocks 

 containing them ("least altered" as they may be) into the ''highly 

 crystalline condition" of "eozoonal" ophite. But Dr. Carpenter seems 

 to misunderstand the objection altogether, as it is not based so much on 

 the mineral structure of the " eozoonal features " as on the fact that they 

 occur best preserved in " highly crystalline " or metamoi-phosed rocks. 



\ Proc. Roy. Irish Acad. vol. x., " Geological Considerations "; ibid. 

 new ser. vol. i., "Isle of Skye Ophite." 



