186 



The Jrish Naturalist, 



October, 



it is fairly evident that few, if any, animals and plants 

 would have had any chance of persisting through such 

 unfavourable conditions. He contends, however, that in 

 all probability a land connection existed between Clare 

 Island and the mainland which facilitated the passage of 

 the fauna and flora. This would make the age of the animals 

 and plants on the island post -Glacial, that is to say, they 

 could only have migrated to the island after the Ice Age 

 had completely passed away from Ireland. 



The theory of the former existence in Ireland of an 

 arctic climate, accompanied by widespread icefields, has 

 been adopted, as already stated, by almost all geologists, 

 and so far it has withstood the criticisms that have been 

 advanced against it. Nevertheless we must not forget that 

 it is only a theory, and that we should lose no opportunity 

 to test the soundness of the evidence on which it rests. 

 Polished and striated stones found in Boulder-clay are 

 generally believed to have been produced naturally by 

 glacial action. But Professor Meunier, of Paris, ^ has carried 

 on experiments for the past twenty years as to the manner 

 in which similar results can be produced artificially. By 

 subjecting a mass of moist clay containing stones and 

 placed on a slope to great pressure, he found that a 

 gradual re -arrangement of the contents took place. 

 He noticed also that the stones became scratched in a 

 manner similar to that observed in Boulder-clay. As 

 the result of these and other experiments, he came to 

 ^he conclusion that most of the polished and striated 

 stones found in Boulder-clay are not produced by 

 glacial action, but in consequence of what he calls 

 " subterranean denudation." Prof. Meunier returns, 

 moreover, to the older view that the Boulder-clay itself is 

 largely the product of marine action aided by icebergs. 

 Unfortunately Prof. Meunier's researches have as yet 

 scarcely passed beyond a small circle of French geologists, 

 and it is only quite recently that he has been prevailed 



' Meunier, Stanislaus : Observations sur la theorie generale des 

 phenomenes glaeiaires et snr Ics galets stries. Proc. Acad. Nat. Sc. Phila" 

 delphia, vol. Ixviii., 19 15. 



