A bird-catcher, wishing to increase his stock of bullfinches, took out his caged bird and his limed twigs and placed them in such a situation of hedge and bush as he judged favorable to his success. It so happened that his own bird was an educated one, such as is usually termed a piping bullfinch. In the first instance a few accidentally thrown out natural notes or calls had attracted three or four of his kindred feather, which had taken their station not far distant from the cage. There they stood in doubt and curiosity, and, presently, moving inch by inch and hop by hop toward him and the fatal twigs, they again became stationary and attentive. It was in this eager and suspended moment that the piping bullfinch set up the old country dance-tune of "Nancy Dawson." Away flew every astonished bullfinch as fast as wings could move, in confusion and alarm. _A Bird Hammock._ In his voyage to India, Sonnerat speaks of a Cape titmouse, the nest of which is made of cotton and is shaped like a bottle. While the female is hatching inside, the male, a most watchful sentinel, remains outside in a pouch or hammock, fixed to one side of the neck of the nest. When his mate moves off and he wishes to follow her, he beats the opening of the nest violently with his wing until he closes it, in order to protect the young from enemies. _Sagacity of a Bird._ In the museum of Brown University, Providence, R. I., is a curiosity in the shape of a bird's nest. Aside from its ingenious construction as a swinging nest, partly suspended by strings and cords carefully woven into it and around the slender branch which holds it, another evidence of the builder's sagacity is given. As the young birds grew, and the nest daily became heavier, the mother saw that the slender twig, about the thickness of a pipe-stem, to which it was attached, could not support it much longer, so she made it secure by fastening a stout cord about it and passing the end around a strong limb above, which steadied it and made it safe. _Change of Sight in Birds._ Birds destined to move in the medium of a very rare atmosphere and which has but little tendency to refract the rays of the sun, have a great quantity of aqueous humor, in order that the light, strongly refracted in entering their eyes, may bring distinct images. Thus birds at heights where they appear to us only as points, perceive the smallest reptile concealed in the grass. But, as presbyte birds do not distinguish objects when brought near, nature has provided for this difficulty, which occurs when they descend from the heights of the air to seize their prey. To provide for this emergency, they have a membrane, by means of which they remove the crystalline lens from the retina; and thus changing the power of the eye by changing the focal distance of objects, as we do with spectacles, they never lose sight of their prey, whether in the air or on the ground. _Nest of the Flamingo._