So fond were the heroes of these apples, and so necessary did they think them to their daily comfort, that they never went on a journey without requesting Idūna to give them one or two, to fortify them against the fatigues of the way. [Illustration: IDUNA GIVING THE MAGIC APPLES.] Idūna had no difficulty in complying with this request; she had no fear of her store ever failing, for as surely as she took an apple from her casket another fell in; but where it came from Idūna could never discover. She never saw it till it was close to the bottom of the casket; but she always heard the sweet tinkling sound it made when it touched the golden rim. It was as good as play to Idūna to stand by her casket, taking the apples out, and watching the fresh rosy ones come tumbling in, without knowing who threw them. One spring morning Idūna was very busy taking apples out of her casket; for several of the heroes were taking advantage of the fine weather to journey out into the world. Bragi was going from home for a time; perhaps he was tired of telling his story only to Idūna, and perhaps she was beginning to know it by heart; and Odin, Loki, and Hœnir had agreed to take a little tour in the direction of Jötunheim, just to see if any entertaining adventure would befall them. When they had all received their apples, and taken a tender farewell of Idūna, the grove--green and fair as it was--looked, perhaps, a little solitary. Idūna stood by her fountain, watching the bright water as it danced up into the air and quivered, and turned, and fell back, making a hundred little flashing circles in the river; and then she grew tired, for once, of the light and the noise, and wandered down to a still place, where the river was shaded by low bushes on each side, and reflected clearly the blue sky overhead. Idūna sat down and looked into the deep water. Besides her own fair face there were little, wandering, white clouds to be seen reflected there. She counted them as they sailed past. At length a strange form was reflected up to her from the water--large, dark, lowering wings, pointed claws, a head with fierce eyes--looking at her. Idūna started and raised her head. It was above as well as below; the same wings--the same eyes--the same head--looking down from the blue sky, as well as up from the water. Such a sight had never been seen near Asgard before; and, while Idūna looked, the thing waved its wings, and went up, up, up, till it lessened to a dark spot in the clouds and on the river. It was no longer terrible to look at; but, as it shook its wings a number of little black feathers fell from them, and flew down towards the grove. As they neared the trees, they no longer looked like feathers--each had two independent wings and a head of its own; they were, in fact, a swarm of Nervous Apprehensions; troublesome little insects enough, and well-known elsewhere, but which now, for the first time, found their way into the grove.