i6o 



CHAPTERS ON EVOLUTION. 



in dealing with the affinities of the Archaopteryx. Finally, as 

 Yogt points out, there is a complete affinity betwixt the scale of the 

 reptile and the feather of the bird. The feather is, in fact, the 

 further modification of the scale ; and we may, therefore, " imagine 

 the ancestors of the Archaeopteryx as lizard-like terrestrial reptiles, 

 having feet with fine, hooked, free digits, showing no modification in 

 ^ their skeleton, but having the skin furnished at different 



points with elongated warts, downy plumes, and rudi- 

 mentary feathers, not yet fitted for flight, but susceptible 

 of further development in the course of generations." 



But that this odd relic of the Oolite leads us 

 decidedly in the direction of the reptiles by its tail 

 and its hand there can exist no reasonable doubt. 

 Scepticism may exist on this latter point, but the doubt 

 is neither of a learned nor of a scientific kind. We 

 may not say that Archaeopteryx actually leads us from 

 | any one bird to any one group of 

 IB reptiles. It rather stands inter- 

 mediately and alone; but even 

 in its solitary position it certainly 

 makes the gulf betwixt the two 

 classes seem less formidable. 



Next in order from the aviary 

 of the geologist may be produced 

 evidence of the existence of reptile- 

 like birds in a most interesting series 

 of fossils obtained from the Chalk 

 of Western America by Professor 

 Marsh. About 1871 a headless bird 

 skeleton was discovered in the 

 Upper Chalk of Western Kansas. 

 This bird evidently resembled 

 our living divers, and was duly christened Hes- 

 perornis regalis. Like our living ostriches, emeus, 

 and their allies, this extinct bird possessed no 

 keel on its breast-bone. It had the merest 

 rudiments of wings ; and certain reptile-like 

 resemblances seen in its haunch-bones made 

 geologists naturally anxious for the realisation 

 of their hopes in the discovery of a complete 

 skeleton. In 1872 fresh discoveries rewarded 

 the patient and indefatigable search of Professor 

 Marsh. Not only were the missing parts of the Hesperornis duly 

 obtained, but the remains of another and still more remarkable 

 species (Ichthyornis dispar) of extinct birds, were duly brought to 



FIG. 82. 

 ICHTHYORNIS JAW. 



