96 THE THEORY OF EVOLUTION 



tially bridged by the Carboniferous group of the 

 Cycadofilices, which, as the name indicates, serve 

 to connect the cycads with the ferns; in ap- 

 pearance of stem and foliage the Cycadofilices most 

 resembled ferns. In view of such facts, it is idle 

 to say, as is still so often said, that the fossils 

 have never afforded transitions between groups 

 which are now radically distinct and widely sepa- 

 rated. 



Another very interesting and significant transition 

 is that displayed by certain fossil birds, which clearly 

 indicate their derivation from reptiles. The relation- 

 ship between birds and reptiles is shown by com- 

 parative anatomy and embryology and is strongly 

 confirmed by the blood tests which were described 

 in the preceding lecture. To this mass of testimony 

 from three independent lines of inquiry, palaeontology 

 adds its quota. At the famous quarries of litho- 

 graphic stone at Solenhofen, in Bavaria, has been 

 found a marvellously preserved record of the later 

 Jurassic life of Europe and here were discovered two 

 nearly complete skeletons of the most ancient known 

 bird, belonging to the genus Archceopteryx. Though 

 an unmistakable bird, Archoeopteryx yet retained 

 many characteristics of its reptilian ancestry, char- 

 acters which are repeated in no existing bird, or 

 appear only as transitory features in the course of 

 embryological development. There is no horny 

 beak, but the jaws are provided with numerous 

 small teeth, which explains the significance of the 



