PHYLOGENETIC 35 



are extremely fine, but they can easily be seen. By the time 

 the adolescent stage has been reached all trace of these separate 

 bones has vanished, leaving the hard, pillar-like "cannon-bone," 

 which reveals no evidence of its earlier compound character. 



So much for the reptilian characters of the skeleton. But 

 the Brain, Vascular and Urino-genital Systems similarly fur- 

 nish proofs of the same derivation. 



So. closely do the birds and reptiles agree, indeed, that 

 Huxley included them together under the term Sauropsida. 



But apart from the indubitable evidence to be obtained 

 from existing birds, other and even more striking evidence is 

 to be obtained from the remains of fossil forms. 



This evidence carries us back to Jurassic times, the oldest 

 known fossil bird, Archaeopteryx, having been obtained from the 

 Lithographic slate of Solenhofen in Bavaria. 



This bird more nearly resembles the reptiles than any 

 other known form. So much so, that undue and unwarrantable 

 use has been made of the fact, many writers having endeavoured 

 to show that it was more reptile than bird, a contention which 

 becomes ridiculous when the facts are carefully considered. 

 Two specimens only of this remarkable bird are known — 

 belonging to as many species — the first to be discovered being 

 now in the British Museum of Natural History, the second in the 

 National Collection of Berlin. With their specific distinctions 

 we have nothing to do here, but both agree in having the 

 jaws armed with teeth and a long tapering, lizard-like tail, but 

 this, like the rest of the body, bore feathers. 



Of all the accounts, and there are many, that have been 

 given of this patriarch of the bird-world only one can be re- 

 garded as accurate, though on many occasions one or other of 

 them have been described by men whose powers of interpreta- 

 tion have in other ways been more severely tried. It is on their 

 descriptions that the inaccurate, and sometimes grotesque 

 figures which adorn text-books of comparative anatomy have 

 been based. So profoundly impressed do these authorities 

 appear to have been by the presence of the teeth, the long tail, 

 the armature of claws on the wings — -concerning which we shall 

 have more to say — and the fact that traces remain only of the 

 wing and tail feathers, and of the feathers of the leg, that they 

 contended that these ancient types must have been clothed 



