238 THE CANADIAN NATURALIST. [Vol. ix. 



are still visible in it, for in ground pieces for the microscope they 

 still shine through. This may be proved by dissolving the limestone 

 by means of acid. Here the leaves are perfectly covered with germ- 

 cells, the " warzenansatze " of Giimbel. This is still clearer wherever 

 the plant has been altered into dolomite. The brood-cells are then 

 visible withont the aid of the microscope. There appear, also, calyx- 

 like cells, clear as water, which have weathered out upon the dolo- 

 mite. 



" But by far the most beautiful are the limestones in which the 

 plants are changed, partly into serpentine, and partly into mica. 

 The same cells are observed in a spar, changed into copper and mala- 

 chite, visible to the naked eye. The canal-systems, therefore, of the 

 " intermediate skeleton " are the microscopical plants which, partly, 

 are simply of a limestone nature or have grown firmly upon large 

 algffi, or are deposited there, dead. As I remarked in the beginning, 

 a key to this new creation is, at all events, necessary. I say new, for 

 it is entirely new to our imagination. The microscopical forms con- 

 stitute this key. Now from these safe premises we may easily come 

 to a conclusion ; but I must here caution against the exclusive use of 

 ground microscopical plates.* It is only by mere accident that, by 

 this means, a view is gained ; hundreds of them may be made, but 

 only a very trained eye can decipher them." 



It seems scarcely necessary to criticise the above statements, 

 as it is probable that very few naturalists will be disposed to 

 accept the supposed plants described by Dr. Hahn as veritable 

 species. It may be observed, however, that in regarding the 

 thick plates of serpentine, interrupted, attached to each other at 

 intervals, penetrated by pillars of calcite, and becoming acervuline 

 upward, as fossil algae, he disregards all vegetable analogies ; 

 while in supposing that the calcite is a filling, and that the deli- 

 cate fillings of canals contained in it are fine thread-like algae, he 

 equally asserts what is improbable. Farther, no vegetable struc- 

 ture or remains of carbonaceous matter have been discovered in 

 the serpentine. Had he discovered these supposed vegetable 

 forms in the graphite of the Lauren tian, this would have been 

 far more credible. 



Hahn's paper, however, suggests one or two points of interest 

 respecting Eozoon, which have perhaps not been sufficiently in- 

 sisted on. One of these is the occurrence of rounded " chaui- 

 berlets " in the calcareous walls. These are his "germ-cells," 



* If this is intended to apply to Canadian and English students of 

 Eozoon, it is quite inaccurate, as they have always employed decalci- 

 fied specimens as well. 



