No. 4.] DAWSOiX — EOZOON CANADENSE. 235 



scale of gneiss into dolomite, limestone, graphite, serpentine, and 

 other minerals, consisting for the most part even of diflferent 

 elements, and this at the same time or by still more mysterious 

 subsequent changes, producing imitations of the most delicate 

 organic forms. The mere statement of this hypothesis is, I 

 think, sufficient to show that it cannot be accepted either by 

 chemists or palaeontologists, and it only serves to illustrate the 

 difficulties which Eozoon presents to those who will not accept 

 the theory of its organic origin. 



Dr. Otto Hahn regards the matter from an entirely different 

 point of view. He has himself visited Canada, has collected 

 specimens of Eozoon^ and now proposes to ejBfect an entire revolu- 

 tion in our ideas of the palaeontology of the Eozoic rocks. 



In a former paper he had maintained that £'ozoo?i is altogether 

 of mineral origin, that its serpentine is hydrated olivine, and 

 the canal system merely cracks in calcite injected by the expan- 

 sion of this mineral. This hypothesis he now finds untenable, 

 and he regards Eozoon as a vegetable production, or rather as a 

 series of such productions. He regards the laminae as petrified 

 fronds of a sea- weed, and the canal systems as finer algae of seve- 

 ral genera and species. Not content with this, he describes as 

 plants other forms found in granite, gneiss, basalt, and even 

 meteoric iron, and others found included in the substance of 

 crystals of Arragonite, Corundum and Beryl, All these are 

 supposed to be algae of new species, and science is enriched by 

 great numbers of generic and specific names to designate them, 

 while they are illustrated by thirty plates representing the quaint 

 and grotesque forms of these objects, many of which are obviously 

 such as we have been in the habit of regarding as mere dendritic 

 crystallisations, cavities, or impurities included in crystals. 



Among other curious discoveries the author refers to a plant 

 which he honours me by naming Photojjhoha Dawmni, and 

 which he discovered in certain " amoeba-like " nodules of flint 

 found in the Silurian of Montreal, and used to adorn the grounds 

 of McGill College. I was puzzled for some time by this, until 

 it occurred to me that at the time of the Doctor's visit some 

 English gravel had been laid on our College terrace, and that 

 several heaps of large irregular flints from this gravel had been 

 gathered in front of the buildings. These had apparently afi"orded 

 the new plant in question. Some other plants stated to be found 

 in hornblende from Montreal mountain, and in limestone said to 

 be called -'fancy stone," are more difficult to account for. 



