LOWER SILURIAN FOSSILS. 33 



true that only the lowest forms of animal life are 

 found in the lowest fossil bands, and that the 

 more complicated structures are gradually de- 

 veloped among the higher bands, in what we 

 might call a natural ascending scale ;" * the pre- 

 text for giving this unqualified contradiction to 

 the above grand fact being, that when we take 

 the special groups of animals, as the invertebrata, 

 the fishes, the reptiles, &c., there are some real or 

 apparent grounds for denying that the low forms 

 of these groups came before the higher. The fallacy 

 consists in sinking the great broad palpable facts of 

 the case, about which not the least doubt anywhere 

 exists, and giving prominence to certain facts of 

 far inferior magnitude, and comparatively obscure, 

 but in whose obscurity there is a possibility of 

 creating a kind of diversion. I trust to be able to 

 show that, even in the special groups of fossils, 

 there is no real obstacle to the theory of a gradual 

 natural development of life upon our planet. 



The view which the Edinburgh critic gives of 

 the earliest stratified rocks is much the same as 

 my own account of them. There is a Hgpozoic 

 formation, or series, devoid of remains of plants 

 and animals ; then a formation {Lower Silurian), 



* " Edinburgh Review." 

 cS 



