NOTES AND MEMORANDA. 275 



Eozoon Canadense. — Dr. Dawson, F.R.S., writing on Professor 

 Mobius' recent treatise, says * that Eozoon Canadense has since the 

 first announcement of its discovery by Logan in 1859, attracted mnch 

 attention, and has been very thoroughly investigated and discussed, 

 and at j^resent its organic character is generally admitted. Still its 

 claims are ever and anon disputed, and as fast as one opponent is dis- 

 posed 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 sus- 

 picion, partly on account of the great age and crystalline structure of 

 the rocks in which it occurs, partly because it is associated with the 

 protean and disputed mineral serjientiue, which some regard as erup- 

 tive, some as metamorphic, some as psoudomorphic. The biologists 

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

 miniferal 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 much 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 fragments of serpentinous limestone, without any struc- 

 ture whatever. He has seen in the collections of dealers and even in 

 public museums, specimens labelled " Eozoon Canadense " which have 

 as little claim to that designation as a chip of limestone has to be 

 called a coral or a crinoid. 



The memoir of Professor Mobius affords illustrations of some of 

 thtse difficulties in the study of Eozoon. Professor Mobius is a 

 zoologist, a good microscopist, fairly acquainted with modern fora- 

 minifera, and a conscientious observer : but he has had no means of 

 knowing the geological relations and mode of occurrence of Eozoon, 

 and he has had access merely to a limited nmuber of specimens 

 mineralized with serpentine. These he has elaborately studied, has 

 made careful drawings of portions of their structures, and has 

 described these with some degree of accuracy ; and his memoir has 

 been profusely illustrated with figures on a large scale. This, and 

 the fact of the memoir appearing where it does (Palseontographica), 

 convey the impression of an exhaustive study of the subject ; and 

 since the conclusion is adverse to the organic character of Eozoon, 

 this paper may be expected, in the opinion of many not fully acquainted 

 with the evidence, to be regarded as a final decision against its animal 

 nature. Yet, however commendable the researches of Mobius may 

 be, when viewed as the studies of a naturalist desirous of satisfying 

 himself on the evidence of the material he may have at command, they 

 furnish only another illustration of partial and imperfect investiga- 

 tion, quite unreliable as a verdict on the questions in hand. 



Dr. Dawson then " indicates the weak points of the memoir," of 

 which the following is a summary. 



* 'Am. Jour. Sci. and Arts,' xvii. (1879) 196. 



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