§ 31. OBJECTIONS CONSIDERED. 585 



oppose these conclusions, and have recourse to the most 

 strange conceits to account for the phenomena on which 

 they are founded. But it is for those who refuse their 

 assent to deductions made with the greatest caution, and 

 derived from an overwhelming mass of evidence, to explain 

 the entire absence of all traces, not only of Man, but of the 

 whole existing species of animals and vegetables, in the 

 ancient deposits ; while there is not a river, or stream, 

 which does not daily imbed the remains of the present 

 inhabitants of the globe. But however future discoveries 

 may modify this hypothesis, they cannot invalidate the fact, 

 that there is no country on the face of the earth with such 

 an assemblage of animal life, as that possessed by the 

 regions whence the delta of the Wealden was derived ; no- 

 where is there an island or a continent inhabited by colossal 

 reptiles only, or where reptiles usurp the place of the large 

 mammalia. We have seen that this feature in the zoology 

 of that remote period was not confined to the country of 

 the Iguanodon ; in every part of the world where geological 

 researches have extended, this wonderful phenomenon 

 appears — the absence of mammiferous animals. The bones 

 of reptiles of enormous size, are the only animal remains 

 that occur in any considerable number. It is, therefore, 

 manifest, that there was a period when oviparous qua- 

 drupeds of appalling magnitude, were the chief possessors 

 of the lands, of which any traces remain in the strata that 

 are accessible to human observation. I do not, however, 

 mean to aver, that reptiles, and reptiles only, were the 

 occupiers of every Island and Continent ; but that it ap- 

 pears from the most irrefragable testimony, that the reptile 

 tribes, during the secondary periods, were developed to an 

 extent of which the present state of animated nature affords 



I should on this occasion have passed over the unjust strictures of 

 Mr. Kirby in silence, had they not been repeated in a late edition of 

 the " Bridgewater Essays." 



