This watercolor, which is exhibited for the first time in Audubon’s Aviary: Parts Unknown, came into the collection from Lucy Bakewell Audubon without an attribution. Whereas it was originally thought to be by Audubon, it has been reattributed to its proper artist, William MacGillivray (see comparative figure), JJA’s editor of the Ornithological Biography, the five-volume “text” of The Birds of America sent to all his subscribers. Audubon hired MacGillivray, the Scottish naturalist and university lecturer, as his highly disciplined professional collaborator, to help him “improve” his “text” for The Birds of America. A friend of Charles Darwin’s and a foil in personality to Audubon, “Mac” helped with scientific information and grammar. The two men quickly forged a mutual admiration society. Mac lent scientific precision that supplemented Audubon’s field observations, which MacGillivray ardently supported. In turn, Audubon taught MacGillivray watercolor techniques, such as an unfinished version of Audubon’s Tricolored Heron watercolor (JJA’s original, 1863.17.213, is exhibited in Parts Unknown). Maria Martin duplicated this same watercolor as a pedagogical exercise for Audubon. Eventually, the Scot learned to execute beautiful watercolors, albeit with a generally grayish, more pastel palette, and flatter forms. He planned to engrave them for his British counterpart to Audubon’s work, but he was unable to afford lavish illustrations. His smaller-scale treatises feature a few black and white engravings. Manual of British Birds (1846) includes them only in its introduction, while A History of British Birds (1837–52) contains mostly figures of heads and alimentary organs (see comparative figure). These illustrations are positive evidence that the 145 anatomical illustrations based on dissections of 107 species in the last three volumes of the Ornithological Biography and the octavo edition of The Birds were by MacGillivray. The Scot believed these organs held the secret to classification, which today rests on DNA in combination with morphological traits.