Palceozoic Fossil Plants. 219 



Petit-Coeur would be more deceptive than any he has ever 

 examined, and until more proofs are obtained to the contrary, 

 he must repeat his belief that the relations of the strata sus- 

 tain the conclusions of M. E. de Beaumont."* 



When we are to choose between two alternatives, a most 

 extraordinary displacement or contortion of stratified masses, 

 or an exception to the laws elsewhere found to prevail in 

 the geological distribution of organic remains, we must duly 

 weigh, not only the singularity of the required nftechanical 

 disturbance, but also the extent of the palseontological ano- 

 maly. When Sir R. Murchison and M. Escher, in a late 

 survey of the Alps, observed a mass of limestone full of Ju- 

 rassic fossils, a quarter of a mile long, resting unconform- 

 ably on strata of the eocene or nummulitic group, in the 

 Canton of Berne and the Orisons, they preferred to imagine 

 any amount of folding of strata and of lateral displacement, 

 rather than believe that an oolitic fauna with its Ammonites 

 and other fossils had re-appeared on the earth after the 

 older tertiary formations were deposited. t In like manner, 

 when I visited the Danish island of Mden in 1836, and found 

 the northern or glacial drift extensively interstratified with 

 white chalk, of which a faithful and more detailed descrip- 

 tion has just been published by M. Puggaard, I stated in 

 your Transactions that we were justified in assuming any 

 amount of engulfment, contortion, or " entanglement" of the 

 beds of the two formations, rather than believe the drift to 

 have been contemporaneous with the white chalk and its 

 flints. J In such cases it depends entirely upon the degree of 

 our faith in the constancy of palseontological results, whether 

 we attach a greater or less importance to superposition ; 

 and, consistently with this principle, geologists who have 

 regarded the coal-plants and Belemnites of the Tarantaise 

 as belonging to the same group, have laboured to shew that 

 the anachronism would not be so great, because the longevity 

 of species in fossil plants, say they, exceeds that which ob- 



* Quart. Journ. Geol. Soc, vol. v., p. 179. t n>id., vol. v., p. 246. 



X Trans. Geol. Soc, Ser. 2., vol. ii., p. 257 ; see Puggaard, Moens Geologie, 

 pp. 118-134(1851). 



