﻿KIMMERIDGE CLAY. 



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an eminent degree. And just as such appendage was essential to the proportion of the 

 active life of these huge cold-blooded amphibians which was spent in the watery element, 

 so such far-produced caudal fin must have been a cumbrous impediment to the way of 

 walking upon dry land pictured in the work giving figures of the caudal vertebrae and 

 other bones of the Cetiosaurus lowgus. 



In the ratio in which the fore-limbs approach the hind ones in size may be inferred 

 the proportion of time spent by the huge reptile on land, and the importance of the share 

 taken by these limbs in such quadrupedal mode of progression : when the Dinosaur 

 betook itself to water its fore-limbs would be, most probably, disposed as in the 

 Crocodiles. 



If, then, the hypothesis that the reduced fore-limbs of Dinosauria receive the most 

 intelligible, and therefore acceptable, explanation, admitting the principle of adapta- 

 tion of structures to functions, agreeably with the analogy of such living animals as 

 are most nearly allied to them in organization ; the notion that Birds, under their 

 wingless conditions, were derived from Dinosaurs may be safely left to the judgment of 

 whomsoever may be disposed to bring unprepossessed and impartial judgment to the 

 consideration of the hypothesis. 



