100 LECTDBEfl '\ EVOLUTIOM m 



//, s/ .. rnw and reA/Ayonm have been discovered 

 have afforded no certain evidence of birds, with 

 th- remarkable exception of the Solenhofen slates. 

 These so-called slates are composed of a fine 

 ned calcareous mud which lias hardened into 

 lithographic stone, and in which organic remains 

 tan almost as well preserved as they would be if 

 they had been imbedded in so much plaster of 

 Paris. They have yielded the Archceopteryx t the 

 existence of which was first made known by the 

 finding of a fossil feather, or rather of the impiv>- 

 sion of one. It is wonderful enough that such a 

 perishable thing as a feather, and nothing more 

 should be discovered; yet, for a long time, nothing 

 was known of this bird except its feather. But 

 by and by a solitary skeleton was discovered which 

 is now in the British Museum. The skull of this 

 solitary specimen is unfortunately wanting, and it 

 is therefore uncertain whether the Airhn-i^teryx 

 possessed teeth or not. 1 But the remainder of tin- 

 skeleton is so well preserved as to leave no doubt 

 respecting the main features of the animal, which 

 are very singular. The feet are not only alto- 

 - ther bird-like, but have the special characters <>f 

 th- feet of perching birds, while the body hail a 

 clothing of true feathers. Nevertheless, in some 

 other respects, Archccopteryx is unlike a bird and 

 lik' a reptile. There is a long tail composed of 



men, discovered in 1877, and at pivsrnt in 

 niUM'iini. slum's an I'Mvllnitly preserved skull with 

 : and th ire digits, all terminated by (.'laws, in the fore 

 limb. 1893. 



