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(From the Canadian Naturalist V^dl.'j^ No. 4.) 



NOTE ON RECENT CONtROVEKSIES RESPECTING 

 •»v«i» EOZOON CANADENSE. 



Bv Princii'al Dawson, LL.D., F.R.S., Ac. 



In ^a' recent article, published in the American Jourruil 0/ 

 iSai^ce, I have rem;»rked that 



^^^Eozoon Canadeiise hnii, since the first anoounocment of its 

 discovery by Logan in 1859, attracted njuch attentioD, and has 

 befen very thoroughly investigated and disoasseii,- and at present 

 its organic character is generally admitted; 8tRt its claims «re 

 e^er and anon disputed, and as fast as one of^enent is disposed 

 of, another appears. This is in great part due tc the fact that 

 so few scietvtific men are in a position fully to apprecistte the 

 evidence respecting it. Geologists and mineralogists look upeii 

 it. with suspicion, partly on account of the great age and crystul- 

 line structure of the rocks in which it occurs, partly because it 

 is associated with the protean and disputed mineral Serpentine, 

 which some regard as eruptive, some as mctamorphic, some as 

 psoudomorphic, while few have had enough experience to enable 

 them to understand the difference between those serpentines 

 which occur in limestones, and in such relations as to prove their 

 contemporaneous deposition, and those which may have resulted 

 from the hydration of olivine or similar changes. Only a few 

 also have learned that Eozoon is only sometimes associated with 

 serpentine, but that it occurs also mineralized with loganite, 

 pyroxene, dolomite, or even earthy limestone, though the .«ierpen- 

 tinous specimens have attracted the most attention, owing to 

 their beauty and abundance in certain localities. The biologiuts 

 on the other hand, even those who are somewhat familiar with 

 foramiuiferal organisms, are little acquainted with the appearance 

 ©f these when mineralized with silicates, traversed with iQiRiite 

 fnineral veins, faulted, crushed and partly defaced, as is the case 

 with most specimens of Eozoon. Nor are they willing to admit 

 the possibility that these ancient organisms may have presented 

 n more generalized and less definite structure than their modern 

 suoceasors. Worse, perhaps, than all these, is the circumstance 

 ihat dealers and injudicious amateurs have' intervened, and have 

 oireulated specimens of Eozoon, in which the structure is too 

 imperfectly preserved to admit of its recognition, or even Diere 



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