BIRDS OF OLD 65 



sprouting quills, found in newly hatched birds of several 

 species, running from the outer, upper part of the leg 

 just below the knee, nearly to the base of the tail. These 

 quills are placed just where, if developed, they would 

 form a sort of winglet on either side, which combined 

 with the tail would afford excellent support for the hind 

 part of the body during flight. Just such tufts of feath- 

 ers are known to have occurred in Archceopteryx (Berlin 

 specimen), and Mr. Beebe concludes that, like the back 

 fins of the flying fish, they served to support the hinder 

 part of the body as the creature sailed or as our 

 English cousins prefer to put it parachuted through 

 the air. For Mr. Beebe doubts that even Archceop- 

 teryx was capable of true flight, believing that the fore 

 limbs, like the hind, were rigidly extended at right 

 angles to the body and not flapped. 



A most striking bit of evidence is the fact that just as 

 overlapping coverts are found above the secondaries of 

 the bird's wing and alternately with them, so the bristle- 

 like quills on the thigh of the pigeon are surmounted by 

 a series of quills placed precisely like the wing coverts. 



The value of any character or piece of evidence does 

 not lie in its size but in its constancy, or in its apparent 

 relation to other characters, so these little bristle-like 

 feathers of the nestling dove, according to Mr. Beebe, 

 hint at a time when, as just noted, they served a use- 

 ful purpose and were sufficiently developed to support, 

 or help support, the hinder portion of the body. At this 

 stage in the development of birds, which should be some- 

 where near the lower Jurassic, about seven million years 

 ago, both fore and hind limbs bore feathers; but 

 neither pair of limbs took an active part in aerial loco- 

 motion, their function being that of planes, purely pas- 

 sive. This phase of the development Mr. Beebe terms 



