The Theory of Evolution 53 



ancestral form is supposed to have become very short, and 

 long feathers to have grown out from its stump which act 

 as a rudder during flight. Flying reptiles with winged fore- 

 legs and a long vertebrated tail have been actually found as 

 fossil remains, as seen in the pterodactyls and in the famous 

 archasopteryx. The latter, which is generally regarded either 

 as the immediate ancestor of living birds, or at least as a 

 closely similar form, possessed a fore-leg having three fingers 

 ending in claws, and feathers on the forearm similar to those 

 of modern birds. It had a long tail, like that of a lizard, but 

 with well-developed feathers along its sides. It had pointed 

 teeth in the horn-covered jaws. Fleischmann proceeds to point 

 out that the resemblance of the hand of archseopteryx to 

 that of the reptiles is not very close, for two fingers are 

 absent as in modern birds. The typical form of the foot is 

 that of the bird, and is not the simple reptilian type of struc- 

 ture. Feathers and not scales cover the body, and give no 

 clew as to how the feathers of birds have arisen. He con- 

 cludes, therefore, that archaeopteryx, having many true bird- 

 like characters, such as feathers, union of bones in the foot, 

 etc., has other characters not possessed by living birds, 

 namely, a long, vertebrated tail, a flat breastbone, biconcave 

 vertebras, etc. Therefore, it cannot be regarded as an inter- 

 mediate form. Fleischmann does not point out that it is just 

 these characters that would be postulated on the descent 

 theory for the ancestor of the birds, if the latter arose from 

 reptiles. Even if it should turn out that archasopteryx is 

 not the immediate forefather of living birds, yet the dis- 

 covery that a form really existed intermediate in many 

 characters between the reptiles and the birds is a gain for 

 the transmutation theory. It is from a group having such 

 characters that the theory postulates that the birds have been 

 evolved, and to have discovered a member of such a group 

 speaks directly and unmistakably in favor of the proba- 

 bility of the transmutation theory. 



