Birds undoubtedly sing for the same reasons that inspire to utterance all the animated creatures in the universe. Insects sing and bees, crickets, locusts, and mosquitos. Frogs sing, and mice, monkeys, and woodchucks. We have recently heard even an English Sparrow do something better than chipper; some very pretty notes escaped him, perchance, because his heart was overflowing with love-thoughts, and he was very merry, knowing that his affection was reciprocated. The elevated railway stations, about whose eaves the ugly, hastily built nests protrude everywhere, furnish ample explanation of his reasons for singing. Birds are more musical at certain times of the day as well as at certain seasons of the year. During the hour between dawn and sunrise occurs the grand concert of the feathered folk. There are no concerts during the day--only individual songs. After sunset there seems to be an effort to renew the chorus, but it cannot be compared to the morning concert when they are practically undisturbed by man. Birds sing because they are happy. Bradford Torrey has given with much felicity his opinion on the subject, as follows: "I recall a Cardinal Grosbeak, whom I heard several years ago, on the bank of the Potomac river. An old soldier had taken me to visit the Great Falls, and as we were clambering over the rocks this Grosbeak began to sing; and soon, without any hint from me, and without knowing who the invisible musician was, my companion remarked upon the uncommon beauty of the song. The Cardinal is always a great singer, having a voice which, as European writers say, is almost equal to the Nightingale's; but in this case the more stirring, martial quality of the strain had given place to an exquisite mellowness, as if it were, what I have no doubt it was, A Song of Love." --C. C. Marble. [TO BE CONTINUED.] [Illustration: From col. F. M. Woodruff. YELLOW-THROATED VIREO.] THE YELLOW-THROATED VIREO. The popular name of this species of an attractive family is Yellow Throated Greenlet, and our young readers will find much pleasure in watching its pretty movements and listening to its really delightful song whenever they visit the places where it loves to spend the happy hours of summer. In some respects it is the most remarkable of all the species of the family found in the United States. "The Birds of Illinois," a book that may be profitably studied by the young naturalist, states that it is decidedly the finest singer, has the loudest notes of admonition and reproof, and is the handsomest in plumage, and hence the more attractive to the student.