286 TowNSEND, Bird Genealogy. [july 



The extension of the so-called thumb or bastard wing in the Pigeon 

 and other birds as they approach their perch may in the same way 

 hark back to the time when the reptilian ancestor grasped with its 

 fore feet its goal on the tree tops. Both young Green and Night 

 Herons elevate the bastard wing at times as they climb about the 

 trees, but I have never seen them attempt to use it for grasping. 



Left with a couple of young English Sparrows on my hands 

 owing to the destruction of their nest caused by the closing of a 

 blind, I dropped them into a basin of tepid water, expecting the 

 inert masses to sink or at least that their wabbly heads would fall 

 below the surface. On the contrary they became endowed with 

 life and vigor as if upon their native heath, and, with a combination 

 of rapid wing strokes and leg action, and with necks outstretched 

 they scudded across the surface of the miniature pond. 



Blood will out, the reptilian ancestry was working! To make 

 sure that this was not an accident I dropped a young Red-winged 

 Blackbird into the pool below his nest. He too performed in ex- 

 actly the same manner and safely reached some reeds up which he 

 scrambled, and was there well taken care of by his excited parents. 

 It is probable that many a passerine bird nesting over the water 

 has been saved from destruction by this return to primitive methods. 



Further experimentation with young Crows and Bronzed Grack- 

 les showed me that very young birds generally moved the wings 

 alternately, while older ones always flapped both together as in 

 flight. From this one would infer that the primitive reptilian 

 scramble was naturally an alternate method while the simultaneous 

 method was simply the more advanced style used in flight. 



In the case of the Chimney Swift the method of flight has been 

 thought to be an alternate flapping of the wings. Let anyone 

 watch these curious birds as they dart with amazing speed through 

 the air, and I am sure he will agree that the wings are used alter- 

 nately with great rapidity. Steady flight by this method is, I 

 believe, mechanically possible. One might argue therefore that the 

 Swifts retain the more primitive or reptilian method of moving 

 the front limbs and are therefore members of a very early branch 

 on the avian tree, although it is possible that through extreme 

 specialization they have returned to this form of flight. 



If this prone method of propulsion on the water on all fours is a 



