LONGEVITY* 349 



their feathers by moulting. Rabbi David adds, 

 that when it delays the operation too long it has not 

 strength to rise from the water, and is frequently 

 drowned *. 



St. Augustine says, that when the eagle becomes 

 very old, the upper mandible of the beak grows so 

 long that the bird can no longer feed, in which case 

 it betakes itself to a rock or rough stone, and rubs 

 its beak till the overgrown part is ground down into 

 proper proportion f- 



Albertus Magnus gives a still more ingenious pro- 

 cess of renewal, not however of his own invention, 

 but quoted from Jorachus and Andelinus, whose 

 works we presume are now lost. " They say," 

 reports Albertus, " that an old eagle at the period 

 the young ones are fledged, as soon as she has dis- 

 covered a clear and copious spring, flies directly 

 upwards even to the third region of the air, which 

 we term the region of meteors, and when she feels 

 warm, so as to be almost burning, suddenly dashing 

 down and keeping her wings drawn back, she plunges 

 into the cold water, which by the astringing of the 

 external cold increases the internal heat. She then 

 rises from the water, flies to her nest, and nest- 

 ling under the wings of her warm young ones, melts 

 into perspiration, and thence with her old feathers 

 she puts off' her old age, and is clothed afresh ; but 

 while she undergoes this renovation, she makes prey 

 of her young for food. But I can only,'* he adds, 

 " consider this as a miraculous occurrence, since in 

 two eagles which I kept I observed no changes 

 of this sort ; for they were tame and docile, and 

 moulted in the same manner as other birds of 

 prey }." 



* Comment. Esaiae, cap. xiv. 



f In Psalm, ciii. 5. 

 I De Animal, xxiii. cap. de Aquila. 



2H 



