July 31, 1879] 



NATURE 



329 



and myself the justice of placing before your readers his state- 

 ment of objections to them, in which I fully concur. 



Hereafter I think I shall be able to show that the "cumu- 

 lative argument in favour of the organic character of Eozoon is 

 as strong as that of the human origin of the "flint implements." 

 Any one of the fractures that has given to these their characteristic 

 forms, might have been accidental ; and yet it is impossible to 

 conceive that any number of such flints can have been so shaped 

 "by accident." William B. C.\rpenter 



Lo:;do;i, July 2S 



The following is the cjiiimunicatiou from Principal Dawson 

 referred to by Cr. Carpenter : — 



F.ozoon canadense has, since the first announcement of its dis- 

 covery 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, 

 wliich 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 mineralised with loganite, 

 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 mineralised with silicates, traversed « ith 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 pre- 

 sented a much more generalised and less definite structure than 

 their modern successors. Worse, perhaps, than all these, is the 

 circumstance that dealers and injudicious amateurs have inter- 

 vened, 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 

 structure whatever. I have seen in the 'collections of dealers, 

 and even in public maseums, specimens labelled ' ' Eozoon cana- 

 dense" 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 Trof. Moebius affords illustrations of some 

 of these difficulties in the study of Eozoon. Prof. Moebius is 

 a zoologist, a good microscopist, fairly acquainted with modern 

 foraminifera, and a conscientious observer ; but he has had no 

 means of knowing the geological relations and mode of occur- 

 rence of Eozoon, and he has had access merely to a limited 

 number of specimens mineralised with serpentine. These he 

 has elaborately studied, and has made careful drawings of 

 portions of their structures, and has described these with some 

 degree of accuracy ; and his memoir has been profusely illus- 

 trated with figures on a large scale. This, and the fact of the 

 memoir appearing where it does, 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 Moebius 

 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 famish only another illustration of partial 

 and imperfect investigation, quite unreliable as a verdict on the 

 questions in hand. The following considerations will serve to 

 indicate the weak points of the memoir : — 



I, A number of errors and omissions arise from want of 

 study of the fossil in situ, and from want of acquaintance with 

 its various states of preservation. Trivial errors of this kind 

 are his referring to my photograph in Plate III. of the "Dawn 

 of Life," as if it were natural size, and his stating that the 

 larger specimens have fifty laminx, whereas they often have 



more than a hundred. More important is his failing to appre- 

 ciate aright the occurrence of Eozoon in certain layers of regu- 

 larly bedded limestones, the rounded or club-shaped forms of 

 the more perfect specimens, the manner in which the layers be- 

 come confluent at the edges of the forms, as described by Sir 

 W. E. Logan and myself, or the amount of crushing and frac- 

 ture which most of the specimens exhibit. Thus he fails to 

 convey any adequate idea of the Stromatoporoid forms and moue 

 of occurrence of the organism, or indeed of its general character 

 and probable mode of growth. Further, he treats it from the 

 first as a mere laminated aggregate of calcite and serpentine, 

 without reference to its occurrence in any other state, and al.o 

 without reference to the fragmental limestones in i)nrt made up 

 of its remains. He objects strongly to the want of definiteness 

 of form and distrlbvition in the chambers and connecting pas- 

 sages, without making allowance for defects of preservation, cr 

 mentioning the similar want of defined form in some Stroinato- 

 fom. lie admits, however, that the modern Carpenteria and 

 its allies are in some respects equally indefinite. Jle further 

 objects to the impossibility of detecting regular |.;-: rary cham- 

 bers like those in modern foraminifera, but seems not to be 

 aware that, as I have recently shown, some Strotnaiopoia 

 originate in a vesicular, irregular mass of cells, and that in 

 Lo/tusia, both the eocene L. Persica and the carboniferous 

 L. Columbiana, the primary chamber is represented by a merely 

 cancellated nucleus.^ 



2. With reference to the finely tubulated proper wall of 

 Eozoon, he has fallen into an error scarcely excusable in an 

 observer of his experience, except on the plea of insufficient 

 access to specimens. He confounds the proper wall with the 

 chrysotile veins traversing many of the specimens, and ob- 

 viously more recent than the bodies whose fis-ures they fill. 

 That he does so is apparent from his stating that the proper 

 wall structure sometimes crosses the bands of serpentine and 

 calcite, and also that it presents a series of parallel four-sided 

 prisms, whereas, when at all perfectly preserved, it shows a 

 series of cylindrical threads penetrating a calcite wall. That 

 some of his specimens have contained the proper wall fairly 

 preserved is obvious from his own figures, in which it is possible 

 to recognise both this structure and chrysotile veins, though 

 confounded by him under the same designation. He objects, 

 somewhat naively, that many of the chambers fail to exhibit 

 this nummuline wall, and that it sometimes presents a ragged 

 appearance or is altogether opaque. In point of fact it can 

 appear distinctly, either in decalcified specimens or in slices, 

 only when the minute tubes are filled with some substance 

 optically distinguishable from calcite, or not acted on by dilute 

 acid. When the proper wall is merely calcareous (and I have 

 specimens showing that it is often in this state, and without 

 any serpentine in its pores), its slracture is ordinarily invisible, 

 and it is the same when the calcareous skeleton has from any 

 cause lost its transparency or has been replaced by some 

 other mineral substance. Even in thickish slices, the tubes, 

 though filled with serpentine, may be so piled on one another 

 as to be indistinct. All this may be seen in tertiary Nummti- 

 lites. When wholly calcareous their tubulation is often quite 

 invisible, and when imperfectly injected with glauconite or 

 other silicates, they often present a very irregular appearance. 

 If Prof. Moebius will study the Nummulites injected with 

 glauconite from Kempten,^ Bavaria, in addition to the casts 

 of PolyslomellairoTa. the ^gean, to which he refers, he will be 

 better able to appreciate these points. It may be worth re- 

 peating here that, in examining the original specimens of 

 Eozoon, I did not recognise the proper wall. I did not doubt 

 that it must have existed in some form, since I could easily 

 detect the canals in the 'supplemental skeleton ; but I did not 

 wonder at its non-appearance, knowing the chances against its 

 preservation in a recognisable form. Its discovery was due to 

 the subsequent investigations of Dr. Carpenter.' 



3. To the canal system. Prof. Moebius does more justice 

 and admits its great resemblance to the forms of this structure, 

 in modern Foraminifera. This indeed appears from his own 

 figures, which well show how wonderfully this structure has 



^ See yourttfilof London Geol. Soc, J-inuary, 1878. 



' I .im indebted to Mr. Otto Hahn for specimens of these most interesting 

 fossils. , 



3 It may deserve mention here that the cirbonifcrous /•"/««//«« very rarely 

 shows it tubulated wall, and that Dr. Canicnier had maintained Us Nummuline 

 affinities before he obtained specimens showing this particular structure. 

 .Structures «o delicate as these are indeed only preser\ed exceptionally in 

 fossil specimens. 



