17-24. The address to Giotto, thrown in here as it is with conversational freedom, is partially explained in lines 184-248. See note on l. 236.
30. By a gift God grants me. The power to re-create vividly and minutely the past. The artists of bygone centuries are called back by his imagination to their old haunts in Florence.
44. Stands One. The "one" (l. 44), "a lion" (l. 47), "the wronged great soul" (l. 48), and "the wronged great souls" (l. 58), all refer to the unappreciated early artists.
50. They. That is, the famous great artists such as Michael Angelo and Raphael. Critics "hum and buzz" around them with praise to which they are indifferent.
59. Where their work is all to do. Their place in the development of art is not yet understood. It must be made clear, Browning thinks, that painters like Leonardo da Vinci (1452-1519) come in natural succession from earlier obscure artists like Dello, that art is a real and continuous record of the human mind and heart.
67. The mastiff girns. When some influential critic snarls, all the imitative inferior critics take the same tone. Cf. Shelley's "Adonais," stanzas 28, 37, 38.
69. Stefano. A pupil of Giotto and called "Nature's ape" because his accurate representations of the human body.
72. Vasari. Author of Lives of the Most Eminent Painters and Sculptors. (Published 1550. Translated by Mrs. Foster in Bohn's Library.) In his studies of art Browning made constant use of this book.
76. Sic transit. Sic transit gloria mundi. "So passes away the glory of the world."
84. In fructu. "As fruit." The fruit of Greek art at its best was that it presented in marble ideally perfect human bodies.