scale ofgnoi^.s into dolomite, limestone, j^raphite, Mcrpcntinc, aud 

 other minerals, consisting for the mcst part even of difFcrcnt 

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

 subsequent chauucs, producinj^ imitations ol' the most delicuti- 

 organic forms. Tiie mere statement of this hypothesis is, 1 

 think, sufficient to show that it ciinnot be accepted either by 

 chemists or |»Mljcoiitol()L>ists, and if (mly serves to illustrate the 

 difficulties which hjor.oon present.- to those who will not accept 

 the theory of its organic origin. 



Dr. Otto llalin regards the matter from an entirely diffiirent 

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

 specimens of I'Jo:j)oii, and now proposes to effect an entire revolu- 

 tion in our ideas df the pahcoiitology of the Eozoic rocks. 



In a former pa|ier he hid miintaiiied that hJozoon is altouether 

 of mineral origin, that its seri>entine is hydrated olivine, iui<l 

 the canal system mt.rely cracks in calcite injected by the expan- 

 sion of this mineral. This hypothesis iie now finds untenable. 

 and he regards J'Jumiou as a vegetable [)roduetion, or rarher as a 

 .s(>ries of such productions. He regards the lamina) as petrified 

 fronds of a .sea-weed, and the canal systi'uis .is finer algte of .seve- 

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

 plants other forms found in gr.mite, gneiss, basalt, and even 

 meteoric iron, and others found included in the substance of 

 crystals of Arragonite. Corundum and Beryl. All these are 

 suppo.sed to be algju of new species, and science is enriched by 

 great numbers of generic and specific names to designate them, 

 while they arc illustrated by thirty plates representing the ([ualnt 

 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 im{)iirities included in crystals. 



Among other curious di.sct)veries the author refers to a plant 

 which he honours me by naming Photophohn D<ncso7ii. and 

 which he diseo\cred iu 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 iu front of the buildings. These had apparently afforded 

 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. 



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