I CAN BUT SING.
Reading edition
"O little bird of restless wing, Why dost thou sing so sweet and loud? Why dost thou sing so strong and proud? Why dost thou sing?" "Oh I have drunk the wine of spring, My mate hath built a nest with me: My hope flames out in song," said he, "I can but sing."

From col. Chi. Acad. Sciences. MAGNOLIA WARBLER. Life-size. Copyright by Nature Study Pub. Co., 1898. Chicago.