1917.] 



of the Australian Black Swan. 



243 



length, hanging from the horny mandible. With every 

 (lip into the freezing water the impediment grew longer. 

 Fortunately, however, the sun soon came out, and the 

 hungry bird, attracted by his friend at the gate, hit on 

 the expedient of knocking his bill against the wall and 

 recovered his power of feeding. 



Text-figure 2. 



Head of the Black Swan with an icicle attached to the 

 lower mandible, about \ nat. size. 



That swans are among the older inhabitants of this cold 

 country is indicated by the remains both of Whooper and 

 of Bewick's Swans in the superficial deposits of Thames 

 gravel. "While fully granting that the bones may have been 

 those of migrant birds, I would suggest that even those 

 contemporaries of the Mammoth are likely to have known 

 how to keep their heads and necks warm in a freezing wind. 

 One might even go further and explain the origin of the 

 gleaming whiteness of the swan as an Arctic characteristic, 

 partly to secure invisibility in snow and partly, as Lord 

 Walsingham'^ would have us believe, to check loss of heat 

 by radiation. Black Swans come from warmer climes, and 

 now, owing to inability, or to ignorance of how to effect a 



* Trans. York. Nat. Union, ser. D. Articulata, 1885, p. 122. 



r2 



