THE ARGUMENT FROM PALEONTOLOGY 65 



In the first edition of the "Origin of Species," 

 Darwin said : " We may thus account even for 

 the distinctness of whole classes from each other — 

 for instance, of birds from all other vertebrated 

 animals, by the belief that many animal forms of 

 life have been utterly lost, through which the 

 early progenitors of birds were formerly connected 

 with the early progenitors of the other vertebrate 

 classes." 



This was a prophecy out of which much capital 

 was made at the time. It appeared an easy way 

 out of the difficulty to suppose extinction and dis- 

 appearance of all those forms whose existence, at 

 one time or another, it was necessary to assume. 

 At the time of the utterance of this prophecy, in 

 1859, there was no positive evidence at all. But in 

 1862, the ArchcBOpteryx (Frontispiece) was shown to 

 be a true bird as regards its feathers and wings, 

 combined with several Reptilian characters, such as 

 the long tail, the nature of the hip-bones, legs, 

 and vertebra?. A second specimen was found in 

 1879, having a skull with numerous teeth, clawed 

 fingers, perfect feathers, and bi-concave vertebrae. 

 In 1868 Professor Huxley showed in fossil reptiles 

 (Dinosaurus) the nature of the modification in virtue 

 of which the quadrupedal reptile passed into the 

 type of a bipedal bird. Again, in 1875, the dis- 

 covery of toothed birds in chalk by Marsh com- 

 pleted the series of transitional forms between 

 birds and reptiles. From that time Darwin's pro- 

 phecy could be replaced by demonstrated facts. 

 There are actual fossils which bridge over the 



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