PROOFS, ILLUSTRATIONS, AUTHORITIES, ETC. XXXV 



quadruped has recently been found imprinted on a Lower Silurian 

 sandstone in North America." 



It is very unfortunate for evidence of this kind, that it is only 

 presented to be immediately after withdrawn. The Canada slabs 

 with chelonian tracks reigned for a time in 1851. Professor Owen, 

 when he had seen only a few, gave his opinion that the peculiarities 

 " pointed to the Keptilia," and he " inclined to refer them to a 

 species of Terrapene or Emydian Tortoise."* The President of the 

 Geological Society gave his countenance to this idea in his annual 

 address of that year. To find that not merely fish, but reptiles, had 

 lived coevally with the hitherto supposed protozoic mollusks and 

 trilobites, was a discovery even exceeding the wishes of such men as 

 Mr. Miller. More slabs, however, came to England; some whispers 

 of doubt began to circulate ; and the learned Hunterian Professor 

 was induced in spring 1852, to give the whole subject a new and 

 more searching investigation. The result appears in a most ingenious 

 and laborious paper, presented, with many illustrations, in the Quar- 

 terly Journal of the Geological Society. Mr. Owen there arrives afc 

 the conclusion that the foot-tracks are not chelonian, but crustacean, 

 thus leaving that early age still invertebrate ! 



Now we are far from saying that remains of fish may not yet 

 be discovered in the Lower Silurian formation ;f but, in the mean- 

 time, it stands as a remarkable fact, that the formation, though 

 much explored, and though lower organisms have been found in it 

 in vast numbers, has not yet yielded any examples of this vertebrate 

 type. And surely, while we admit that such negative evidence can 

 never be equal to positive in value, there must be some limit to our 

 inferior appreciation of that kind of proof. It ought surely to be 

 remembered that, if there be not fish in that formation, we never can 

 have any but negative proof of the fact. 



The various announcements of fossil fish below the Wenlock lime- 

 stone have ended in such discredit to all concerned, that comment 

 on the subject is unnecessary. It seems fair, however, to hint that 

 the eagerness and facility which have been shown in admitting facts 

 against the development hypothesis, even when they were of that 

 isolated character which is most apt to excite suspicion, scarcely 

 comports \vith the caution which men of science so loudly demand. 

 It may be asked, is there only to be caution in admitting lacts which 

 contribute to the support of a hypothesis ? Is heedless haste to be 

 allowable where the hunting down of a hypothesis is in view P If 

 so, it is proper that the public should be made aware of it, so as to 



* See Geol. Jour. vii. p. Ixxvi. 



f It is nevertheless remarkable that the admitted evidence of fish even in 

 the Upper Silurian formation has sustained a diminution, rather than an 

 addition, since the first publication of this work in 1844. See papers in the 

 Journal of the Geological Society for February, 1853, in which a great number 

 of the so-called ichthyic fossils of that formation are detected as being frag- 

 ments of crustaceans, leaving barely a representation of this vertebrate type 

 in any portion of the Silurians. 



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