Flip said no more; but he formed a strong opinion about Twinkle, and felt that he did not care for his company any longer. Watching his opportunity, while the other was at work on a fly, he flitted quietly into the thick of the alders on the other side of the round pond, and taking a perch right down in the roots by the water, began to give vent to his own sorrow by uttering a sad cheep every minute or two. Poor Pipi, the kindest and the cleverest of them all! always helping some one, and always in good humour! never without some little fun of his own, even in the most awkward moments! How could they possibly get back again to Africa, when the summer was over, without Pipi? How indeed would Flip have the heart to sing to his wife during the nesting-time, unless Pipi’s voice was heard from the next tree? Pipi was always singing, and his voice was the best of all: for while the others were always finding their voices go up with a turn at the end of their strain, like those commonplace chaffinches, Pipi almost always brought down his in a perfect cadence, which is the great accomplishment of a willow-warbler. And when the young were fledged, no young father of a brood was so careful or so beloved as Pipi. _He_ did not leave all the work to his wife, as some did; Mrs. Pipi had been hard-worked ever since they built their nest at the foot of the big elm-tree, and now she was sent off every day in the early morning to eat her fill of insects in a neighbouring garden, with a special warning to beware of the old gray cat, who was always creeping about between the pea-rows. Then Pipi used to take the young ones under his own charge, and put off his own breakfast till he had fed them well, popping the food into their gaping beaks as fast as if his wife had been there to help him. What fun he used to make of them! Flip remembered how he was once sitting on a bough, singing to his own wife, who had not yet hatched all her eggs, when he saw Pipi trying to entice his young ones out of the nest. They all came out at last, except Dot the youngest, who sat at the door of the nest, and looked through the buttercup stems into the wide world with fearful and restless eyes. Pipi tried all he could to make her come out; he perched on the bough above her and sang his best, so that her little black eyes twinkled, for she knew that music well; but still she hesitated. Then he picked up a little green caterpillar and put it down just in front of her; her bill opened wide at the sight of such a juicy morsel, but still she did not come. Just then a snail came slowly by, with its shell on its back.