The American Museum Journal 



Volume XVI 



JANUARY, 191G 



Number 1 



The Beginnings of Flight 



Bv FREDERIC A. LUCAS 



THE recent recognition by Mr. C. 

 William Beebe, curator of birds 

 at the New York Zoological Park, 

 of certain feathers on the hind legs of the 

 young of modern birds, ^ which according 

 to his view may have served the purpose 

 of wings in ancestral birds, brings up 

 anew that ever fascinating problem, 

 " How did flight begin? " and this in turn 

 is inseparably connected with that other 

 problem, "How did birds begin? "- 



The answer to this latter ciuer\' is 

 seemingly as far off as it was fifty -four 

 years ago when the first Archceopieri/.v 

 came to light in the famous quarries of 

 Solenhofen. We are pretty siu'e that 

 birds branched off from reptiles, fairly 

 sure that they must have started as far 

 back as in the Trias or even Permian, 

 when the curious anomodonts faintly 

 foreshadowed the coming mammals. 

 But just what form gave rise to birds 

 we know not; we have not e\'en any 



' "The Tetrapteryx Stage in the Ancestry of 

 Birds," by C. William Beebe, curator of birds, the 

 New York Zoological Park. Published in Zoologica, 

 Vol. II, No. 2, 1915. 



- Fifteen million years ago, in the middle of the 

 Pateozoic or second great period of the earth's history, 

 the Age of Fishes was just drawing to a close. The 

 only vertebrate animals that could live upon land were 

 the primitive, froglike batrachians, and even these 

 were probably much more at home in the water. ' 



We have no record of the myriad different types 

 of creatures that succeeded these first dwellers on the 

 land, except their fossil remains found buried in the 

 rocks of the various geologic a^es, and this record is far 

 from complete. Hence, although we believe that the 

 higher vertebrates — reptiles, birds and mammals — 

 are derived from the slow-crawling, cold-blooded, 

 small-brained primitive batrachian, it is not possible 

 to trace the successive stages of the descent. 



living bird that shows such strong traces 

 of reptilian origin as do the monotremes 

 among mammals. 



Like Mr. W. P. Pycraft, Mr. W. DeW. 

 Miller and the ^vl■iter, there are some 

 even so heterodox as to believe more or 

 less firmly that possibly birds had not 

 one, but two points of origin, and to 

 feel that if we could follow back their 

 lines of descent we should find that the 

 ostriches came from one, and the birds- 

 of flight from another. And why not? 

 Is it any more strange that Nature 

 should have repeated herself once than 

 that all our birds should have been de- 

 rived from one pair of ancestors? 



Such heretics — and a heretic is 

 merely one who differs from the major- 

 ity — such heretics as believe in this 

 so-called "diphylletic" origin of birds 

 cannot help propounding the queries, " Is 

 the ostrich big because he doesn't fly?" 

 or "Doesn't he fly because he is big?" 

 or "Did he never fly at all?" Those 

 who bring forward the ever-ready fact 

 that the embryology of the ostriches 

 seems to indicate that they are de- 

 scended from forms that flew, are re- 

 minded that embryology is not regarded 

 as so decisive in its testimony as it was 

 fifty years ago. 



We are all familiar with the ready 

 argument that such extraordinary struc- 

 tures as feathers could not have been 

 developed twice, but this is not a whit 

 more strange than that they should have 



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