FOSSIL BONE. 643 



furnished by the configuration of the bones, not being in any 

 degree decisive, the question would have remained unsettled, had 

 not an appeal been made to the Microscopic test. This appeal 

 was so decisive, by showing that the minute structure of the bone 

 in question corresponded exactly with that of Pterodactyle bone, 

 and differed essentially from that of every known Bird, that no 

 one who placed the least reliance upon that evidence could enter- 

 tain the slightest doubt on the matter. By Prof. Owen, however, 

 the validity of that evidence was questioned, and the bone was 

 still maintained to be that of a bird ; until the question was finally 

 set at rest, and the value of the microscopic test triumphantly 

 confirmed, by the discovery of undoubted Pterodactyle bones of 

 corresponding and even of greater dimensions, in the same and 

 other chalk quarries.^ 



' See Prof. Owen's Monograph on the British Fossil Reptiles of the Challc Formation, 

 p. 80, et seq. 



