1867.] 



and Affinities o/Eozoon Canadense, 



505 



ordinary meclianical or cliemical infiltration, also bearing in mind the 

 . significant fact tliat tfie ' intermediate skeleton,' in Irish and other 

 varieties of eozoonal rock, contains modified examples of the 'definite 

 shapes ' more or less resembling the crystalline aggregations and pris- 

 matic lumps in primary saccharoidal marbles — that eozoonal structure 

 is only found in metamorphic rocks belonging to widely separated 

 geological sj^stems, never in their unaltered sedimentary deposits, — 

 taking all these points into consideration, also the arguments and 

 other evidences contained in the present memoir, we feel the conclusion 

 to be fully established, that every one of the specialities which have 

 been diagnosed for JEozoon Canadense is solely and purely of crystalline 

 origin : in short, we hold, without the least reservation, that from every 

 available standing point — foraminiferal, mineralogical, chemical, and 

 geological — the opposite viev/ has been shown to be utterly untenable.'"' 



Considering that the Eoraminiferal characters of Eo^oon Canadense 

 had been unhesitatingly accepted by all those zoologists, Continental 

 as well as British, whose special acquaintance with the group gave 

 vv^eight to their opinion, it might have been prudent, as well as becoming, 

 on the part of the Galway Professors, to express themselves somewhat 

 less confidently in regard to its purely mineral origin. The case they 

 made out would not have lost any of its real strength, if they had 

 simply put forward their facts as afi*ording valid grounds for questioning 

 the received doctrine. And a way of escape would have been left for 

 them, if the progress of research should happen to bring to light con- 

 clusive evidence on the other side. 



Although such conclusive evidence is now producible, it may be well 

 for me briefly to point out what I regard as the fundamental fallacies 

 in the argument of Professors King and Eowney. 



In the first place, the Serpentine-Marble of Connemara, on which 

 their investigations had been chiefly conducted, is admitted by every 

 one who has examined it to have undergone a considerable amount 

 of metamorphic change. To myself, as well as to Professors King and 

 Eowney, the evidence w^hich it presents of the operation of chemical 

 and physical agencies is most obvious and conclusive ; whilst the evi~ 

 dence of its organic origin rests entirely on its partial analogy to tlie 

 eozoonal rock of Canada. Hence an entire surrender might be made of 

 the organic hypothesis as regards the Connemara marble, without in 

 the least degree invalidating the claim of the eozoonal rock of Canada 

 to an organic origin. But, on the other hand, if the latter claim can 

 be sustainedj'it may be fairly extended to the " Irish Glreen," should 

 the evidence of similarity be found suiiicient to justify such an ex- 

 tension ; since it must be admitted by every Petrologist, that no amount 

 of purely mineral arrangement in a Metamorphic rock can disprove 

 its claim to Organic origin, if that claim can be shown to be justified 



2 T 2 



