114 THE CANADIAN NATURALIST. [Vol. ix. 



can predicate the structural details of the next discovered plant 

 or animal, however narrow the limits we may suppose to define 

 its alliance to any previous known form ? 



Although many mineralogists regard the eozoonal rock as hav- 

 ino- been as inorganic in its origin as it now is in its material, yet 

 Dr. Sterry Hunt, for one, who has long studied it, thinks that 

 its peculiarities are not due to a mineral genesis alone. We 

 know also that not only Foraminiferal shells, but other calcareous 

 tests and skeletons, both recent and fossil, have their tubes and 

 cavities filled by various minerals, with results very similar to 

 what is regarded as having taken place and as being visible in 



Eozoon . 



It is not that here and there, and, indeed, in very many parts 

 of a true Eozoonal rock there are lines and patches, fibrous and 

 concretionary, of purely mineral origin, as well as their mineral 

 matrix, — the point to be kept in view is that the structure of 

 certain portions is best explained by reference to mineral infiltra- 

 tion of tubular and cavernous shells, which grow and spread 

 alter the manner of Foraminifera, though not identical with any 

 known form in particular. Also it has to be remembered that 

 not only has the enclosing rock been itself subjected to mineral 

 chanoes, but has been crushed, broken and twisted, and that the 

 scarcity of large areas of perfect and undisturbed structure, in 

 such a relatively large Rhizojpod, has to be supplemented, in the 

 study of its whole, by such diagrammatic constructions of what 

 the experienced observer recognizes and wishes to explain, as our 

 author condemns at p. 188, because, he thinks, the Eozoonists in 

 their diagrams have overstepped the line of probability. Without 

 such illustrations, showing (like models) both the elevation and 

 perspective of internal arrangements, we may remark, external 

 appearance and microscopic sections would very imperfectly eluci- 

 date the descriptions of large Foraminifera. The correlation of 

 the mineral representatives of, at least, the " canal-tubes " and 

 " chambers " in Eozoon, both of which are cut at many different 

 angles in sections, and can rarely be seen in elevation, and then 

 only to a small extent, are best shown by this method — especially, 

 too, as the student has, in this case, to make a mental translation 

 of threads into tubes, and nodules into chambers. 



At page 198 Prof. Mobius consoles the Eozoonists with his 

 opinion that the doctrine of evolution need not be despaired of 

 because he removes the primordial Eozoon from the category of 



