TUDOR SPECIMEN OF EOZOON. 351 



photograph, a copy of which has kindly been presented by Mr. H. 13. 

 Woodward to the British Museum (Nat. Hist.). The third set of 

 structures are the white calcite-bands for which an organic origin 

 is claimed. These consist of veins of crystalline calcite, which 

 raiely extend to a do})th of more than -jL^ inch. Their relations to 

 the rest of the rock are very irregular. They may end off abruptly 

 or break up into slender ramifications, which are sometimes connected 

 by other calcite-bands developed along the cleavages, so that a reti- 

 culate series results (see fig. 4, facing p. e354). The boundaries 

 between the " Eozoonal " layers and the normal calc-mica-schist are 

 excessively irregular, as is seen in fig. 3 ; there is no " proper wall '^ 

 to be seen at the junction — at least, I have been unable to recognize 

 even such traces as might have been expected had the pores been 

 obliterated by the infiltration of calcite, as has been suggested *. Nor 

 does the evidence for the canals seem more satisfactory. Sir J. W. 

 Dawson figured t as such a series of carbonaceous inclusions, and 

 though by the kindness of Dr. Selwyn I have been enabled to study 

 the original slide, I fail to see any reason for regarding them as the 

 infillings of organic canals. There seems no essential difference 

 between the graphitic bodies in the matrix and those in the calcite, 

 though the latter are as a rule more minute in size. In their 

 irregularity of form and arrangement they seem to be very different 

 from the canals in any known foraminifer. Sir J. W. Dawson's own 

 figure, magnified though it is 120 diameters, fails to carry conviction 

 of the origin which he assigns to them. 



After a careful examination of all the slides and figures, and con- 

 sideration of Sir J. W. Dawson's interpretation, 1 must confess 

 myself absolutely unable to recognize in the specimen any trace of 

 the " proper wall," " canals," or " stolon passages " which are claimed 

 to occur in EozoonX^ or any reasons for regarding the calcite bands 

 as the " intermediate skeleton " of a foraminifer. There are points 

 in Sir J. W. Dawson's figure which might pass as " stolon passages," 

 but these appear very different in the photograph, and the specimen 

 agrees with the latter. 



But the case against the organic origin of the Tudor specimen 

 does not rest on negative evidence alone : in addition there seems 

 plenty of positive proof against this view. The circumstance that 

 while the rock has been intensely cleaved and crumpled the twin 

 laminae and the planes of crystalline cleavage in the calcite-bands 

 are not bent, suggests that the bands are of secondary origin ; and 

 this seems to be conclusively established by the fact that the bedding- 

 planes can be often traced right across the specimen, traversing the 

 limestone in the supposed body-cavities, and broken only by the 

 calcite-layers (see fig. 1). This is faintly indicated in the photograph 



* Quart. Journ. Geol. See. vol. xxiii, (1867) p. 259. 



t Ihid. pi. xii. fig. 1. 



\ But it should be noted that Dr. Carpenter abandoned the view of the 

 organic origin of the ' proper wall': see Whitney & Wadsworth, ' The Azoic 

 System and its proposed subdivisions,' Bull. Mus. Comp. Zool. (Harvard) \ol. vii. 

 (i884) pp. 535-530, and J. W. Gregory, ' Science Gossip,' vol. xxiii. (1887) p. 103. 



