90 SYLVAN SECRETS. 



a guttural squawk, or a metallic clanging 

 scream, being the extent of their performance. 

 Taking the skeleton of Hesperornis regalis, 

 as restored by Marsh, we shall see at once, 

 considering the toothed jaws and reptilian 

 throat, that its vocal organs were probably 

 far inferior to those of existing loons and 

 grebes, if it had a voice at all. 



Eeturning to Archseopteryx, we shall be- 

 come more and more convinced, the more we 

 study its remains in the light of all that is 

 known of comparative anatomy, that it was 

 scarcely more ornithic than our common bat, 

 as regards similarity 10 the birds of to-day, 

 notwithstanding its feathers. Indeed, it had 

 a sort of bat claw at the end of the wing, and 

 its wing feathers and retrices were a very lit- 

 tle remove from the leathery, bat vans of the 

 flying reptiles in so far as efficiency was con- 

 cerned ; but its impression in the rocks regis- 

 ters a definite effort of nature in the direction 

 of evolving a true bird. Thenceforward we 

 may look for feathered forms gradually 

 growing toward the high type of to-day. The 

 reptile prototype has somehow exchanged his 

 scales for feathers ; the generation of the true 

 bird has begun with Archseopteryx. A long, 

 dreary blank here appears in the record of the 

 rocks, after which we find the toothed birds 

 of Professor Marsh, probably full-fledged, 

 in the sense of being coated with feathers. It 

 is to be doubted whether any of these were 

 good flyers, some of them certainly could 

 not fly at all, though they were mostly ex- 

 cellent swimmers, and possibly capable of liv- 

 ing a long time under water, if not really am- 

 phibious. What Professor Marsh says of the 

 anatomy of Archaeopteryx may be applied 

 generally to the toothed birds : ' ' The bones 



