WHEN Robert Louis Stevenson was thirty-three, he surprised his old nurse, “Cummie,” with the announcement that he meant to dedicate to her his first volume of poetry. She, he told her, in the letter from Nice containing this news, was the only person who would really understand it. “He must have felt that he was doing a piece of work altogether admirable,” is the comment of Professor William P. Trent upon this pretty incident, and, adds this subtle critic, “he made a wonderfully successful book because he based it on real experience” — he had taken walks in “A Child’s Garden of Verses,” swung in its trees, peeped over its wall. Marred as his boyhood had been by illness, adds Professor Trent, “it had been that rare thing in these modern days,” a true childhood. For that one reason was it possible for him to produce such a masterpiece of verse for the young as that beginning: “We built a ship upon the stairs.” “Underwoods” was a book of poetry for older readers, brought out simultaneously in London and New York. It went into a second edition speedily, and thus cheered Stevenson in the gloom of his illness among the Adirondacks. “In the verse business I can do just what I like better than anything else,” wrote Stevenson to a friend. Yet Professor Trent doubts if Stevenson’s verses represent him fully.