On the Structure and Position of Eozoon Canadense. 299 



evidence, when microscopically examined, of having been made 

 up of an aggregation of fragments of the proper walls of the 

 chambers of Eozoon; these fragments presenting the most 

 beautifully preserved examples I have yet seen in transparent 

 section, of the characteristic Nummuline tubulation. And as 

 these sections presented no indication of such remains of a 

 canal-system as would have marked the presence of fragments 

 of the intermediate skeleton, I am disposed to think that the 

 breaking-up of the surface of the original Eozoon must have 

 taken place before the proper walls of its highest tiers of 

 chambers had been strengthened by exogenous deposit. 

 Further, in sections of Laurentian limestones, which did not 

 exhibit to the naked eye any evidence of organic structure, 

 Dr. Dawson was able, by microscopic examination, to recog- 

 nize minute fragments, of whose derivation from Eozoon there 

 could be no reasonable doubt. 



Hence, it would appear that these gigantic Khizopods per- 

 formed, in the seas of the Laurentian epoch, the same part in 

 the production of limestone rocks which was subsequently 

 taken by Coral polypes, Echinoderms, and Mollusks, as well as 

 by minuter forms of Foraminifera. And it is a fact not without 

 an important significance, that this, the lowest type of animal 

 life known to the Physiologist, should have thus culminated in 

 the very earliest period in the history of the life of our globe with 

 which the Palasontologist is at present acquainted. If, as I con- 

 sider, that we are quite justified in doing, we refer the animal of 

 Eozoon to the type whose characteristic features we are able to 

 study in our existing Rotalice and Miliolce, we may say of it, 

 as I have elsewhere stated of the Foraminifera generally,* that 

 its substance " does not present any such differentiation as is 

 necessary to constitute what is commonly understood as ' or- 

 ganization/ even of the lowest degree and simplest kind ; so 

 that the physiologist ha3 here a case in which those vital 

 operations which he is accustomed to see carried on by an 

 elaborate apparatus, are performed without any special instru- 

 ments whatever — a little particle of apparently homogeneous 

 jelly changing itself into a greater variety of forms than the 

 fabled Proteus, laying hold of its food without members, 

 swallowing it without a mouth, digesting it without a 

 stomach, appropriating its nutritious material without ab- 

 sorbent vessels or a circulating system, moving its parts with- 

 out muscles, feeling (if it has any power to do so) without 

 nerves, propagating itself without a genital apparatus, and 

 forming a shelly covering that possesses a symmetry and com- 

 plexity not surpassed by those of any testaceous animals." It 

 is not possible to conceive any living being of greater simplicity 

 * Introduction to the Study of the Foraminifera, Preface, p. vii. 



