1868.J KING AND ROWNET "^^ EOZOONAL" KOCK. 117 



ophites, though some are wanting in other ophites, just as they are 

 not always present in the Eozoonal rock of Canada. 



Serpentine has been described as having been deposited in the 

 cavities of Eozoon, and having taken the place of its sarcode ; but 

 the authors criticised all the quoted analogies of such a precipitation 

 of any siliceo-magnesian substance, which they disbelieve, and put 

 aside glauconitic infiltration as beside the question. 



Considered geologically, with referrence to its occurrence in a 

 metamorphic rock, the authors regarded the Eozoon as an organic 

 impossibility ; and they asked why it should never be found in any- 

 thing but crystalline or semicrystalline rocks — in ophites or ophi- 

 calcites of widely different ages. Particularly they found eozoonal 

 structure in the Liassic ophite of Skye ; and this they described in full. 

 They criticised Sterry Hunt's change of opinion, who used to think 

 that the serpentinous rocks of Canada were once earthy amorphous 

 silicates, and afterwards metamorphosed, but who now supposes 

 they were deposited in a crystalline state ; and they asked why, if 

 so, may not all the Laurentian rocks have been so deposited ? In 

 conclusion, they totally denied that Eozoonal structure has anything 

 to do with any organism, and repeated that, Kke all analogous con- 

 ditions of serpentine, chondrodite, &c., it is of purely mineral origin. 



Discussion. 



Prof. Ramsay had been struck long ago by the organic appearance 

 of the structure now regarded as Eozoon. He had also felt a diffi- 

 culty in accounting for the existence of large masses of limestone, 

 except by the operation of organisms living in the sea, in which such 

 deposits had been formed. He could not imagine the sea-water so 

 overcharged with calcareous matter as spontaneously to deposit 

 limestone. 



Mr. Paekee, on examining the various parts of the Eozoon as 

 shown him by Dr. Carpenter, had been able to recognize in them 

 similar structures to what he had already met with in recent 

 Poraminifera. 



Prof. T. Rfpert Jones accounted for the difficulty that sometimes 

 existed in recognizing Eozoonal structure by the contortion of the 

 containing beds subsequently to their deposition. 



Dr. Duncan had been struck in the earlier known specimens of 

 Eozoon by the shape of the tubules of the canals: he had never 

 seen similar outlines in inorganic bodies. 



Dr. Caepentee need not repeat the grounds on which he regarded 

 Eozoon as an organic structure. He objected to criticisms unless 

 founded on examination of actual specimens, and regretted that 

 Prof. King had not examined the large collection of specimens in 

 his (Dr. Carpenter's) collection. A specimen which Sir William 

 Logan had brought from Canada contained much iron, and had 

 the Canal-system wonderfully preserved; and it presented this 

 character — that the larger branches were infiltrated with serpentine, 

 and the middle branches with sulphide of iron, while the smallest 

 branches were filled with carbonate of lime, of the same nature as the 



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