No. 4.] DAWSON — EOZOON CANADEXSE. 237 



" I found the species which I tiist called Eophi/llum in a piece of 

 Eozoon^ in the first white band of limestone overlying a layer of ser- 

 pentine ; in other Avords between two layers of serpentine. Then first 

 this question occurred to me : Are not the whole lumps of Eozoon 

 plants ? I was forced to yield to the inference after I had exposed, by 

 applying Hydrochloric acid to the limestone, some larger lamellae 

 which were in connection with serpentinic layers ; indeed, the forms 

 are so permanent and so constantly reappearing that they cannot be 

 explained otherwise. Of course with this there was gained the best 

 argument against the animal theory ; for, hitherto the discovered 

 species of Alga3 have never been found in either stones or shells. 

 This plant belongs to the family of the Algfe. They either rest im- 

 mediately upon dolomite and gneiss, or, are found in the proper 

 Eophyllous limestone, i.e. in the layers of serpentine limestone, be- 

 tween the large strata of dolomite and serpentine. They are, however, 

 not only to be found in the limestone, but also in the serpentine of 

 the strata. No plants or but few, are found in the thick layers of ser- 

 pentins which enclose the Eophyllous limestone ; certainly none in 

 the lowest. Some of them may be seen Avith the naked eye, while 

 with the microscope, we come to the smallest conceivable forms. 

 Being replaced by silicates, they may be exposed by the application 

 of acid to the limestone. This done, the plants make their appearance 

 as shining white stems, calyxes, and leaves. In thinly ground plates, 

 they appear a yellowish brown. This, probably, is the reason that 

 Mobius describes their color as being a light brown. In reality, it is 

 the refraction of the light in the opaque masses." * 



" There was scarcely ever a more ditficult task given to natural 

 science, than the determination of the nature of ^^ Eozoon^ When I 

 made my first announcement of Eophiillum in the "Ausland" I little 

 thought that the large ribbons of serpentine were also plants. I had 

 already half-finished this work after my original plan, when I came 

 across a defective specimen of rock, in which, in consequence of its 

 defectiveness, the serpentine parts were very clearly distinguishable. 



" I looked at it over and over again, till it struck me that the 

 sarcode-chambers were nothing but cells of plants. Thus the fate of 

 the microscopist is decided. What others can see with the naked 

 eye Le does not see at all. Then came the more difiicult part : the 

 examination of the case. Now, I had no more doubt. And in this 

 manner only facts become clear. The ribbons of serpentine which 

 constitute that which is called Eozoon, belong to an alga with broad 

 leaves — if the expression is permitted — which radiating from one point 

 arranges itself in regular forms. The basal-cell rests upon serpentine 

 or dolomite. Roots I found only in one case, of which, however, I am 

 not sure. The limestone is the replacing-material. The germ-cells 



* Thus far, the author refers principally to the serpentine casts of 

 the canal system. 



