228 THE CANADIAN NATURALIST. [Vol. ix. 



NOTE ON RECENT CONTROVERSIES RESPECTING 



EOZOON CAXADENSE. 



By Principal Dawson, LL.D., F.R.S., &c. 



In a recent article, published in the American Journal of 

 Science, I have remarked that 



" Eozoon Canadense has, since the first announcement of its 

 discovery by Logan in 1859, attracted much attention, and has 

 been very thoroughly investigated and discussed, and at present 

 its organic character is generally admitted. Still its claims are 

 ever and anon disputed, and as fast as one opponent is disposed 

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

 so few scientific men are in a position fully to appreciate the 

 evidence respecting it. Geologists and mineralogists look upon 

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

 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 metamorphic, some as 

 pseudomorphic, 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 logauite, 

 pyroxene, dolomite, or even earthy limestone, though the serpen- 

 tinous specimens have attracted the most attention, owing to 

 their beauty and abundance in certain localities. The biologists 

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

 foraminiferal organisms, are little acquainted with the appearance 

 of these when mineralized with silicates, traversed with minute 

 mineral 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 

 a more generalized and less definite structure than their modern 

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

 that dealers and injudicious amateurs have intervened, and have 

 circulated specimens of Eozoon, in which the structure is too 

 imperfectly preserved to admit of its recognition, or even mere 



