Alfred G. Mayer created his butterfly wing projections during a brief period of insect research before he turned to the study of marine life that would cement his reputation as a scientist. Each big block of color is an attempt to represent the range of tonal variation on a single butterfly species’ wings. Within each block are an array of individual examples taken from the entomological collection of the Museum of Comparative Zoology at Harvard University. The vertical lines demarcate individual wings, distorted and stretched mathematically to fill a tidy rectangular space — an arrangement that Mayer hoped would lead to new insights into natural patterns and laws. In his introduction, Mayer proposes a series of “laws of color-patterns”: he notes bilateral symmetry, the linear arrangement of spots, how bands of color emerge and taper off. The degree of variation within a species, or between males and females: the rules and their exceptions.

Mayer’s exercise is a descriptive one, a question of comparison and juxtaposition. The pattern-bending projections he developed served his interest in contrasting these minute insect mosaics. But we might also imagine these vibrant illustrations as a personal indulgence for a man enamored, since childhood, by butterflies and the colors of the natural world. As a boy, Mayer wrote, “I literally loved individual butterflies I had raised from early larval stages, and exulted in their imagined joy as they flew from my hand to flutter over the cloverladen fields.” He describes a solitary childhood, “wherein I lived apart from man, and sought my playmates among the creatures of the woods and fields.” The zenith of his childhood memories, Mayer recalled, was “a blue-purple butterfly (Basilarchae ursula).”

Honoring this passion meant picking up paintbrush and pencil, executing butterflies “in extraordinarily lifelike fashion” such that “the iridescent and shimmering wings [seemed] pasted on the page.” It was this passion for the natural world — and for reproducing it in incandescent color — that guided Mayer’s career. This “apparently innate” bend, writes a contemporaneous biographer, drove Mayer to zoology, and away from physics (the profession favored by his father), where his studies “had been failures, due largely to a dislike of the subject.” His passion guided him, eventually, to the laboratory of Alexander Agassiz (famed Harvard natural historian Louis Agassiz’s son), where Mayer would produce the studies and gorgeous illustrations of medusae jellyfish he is remembered for today.

Not everyone was a fan of his Lepidoptera images. Only two months after its publication, Alfred Russel Wallace, renowned Victorian naturalist and co-author of natural selection theory, took to the journal Nature with a damning reproach of On the Color and Color-Patterns of Moths and Butterflies. A leading public intellectual, Wallace offered a brief but sharply critical book review. His grievances are several: though Mayer “has made some interesting experiments and observations”, Wallace allows, “his results are neither so novel nor so important as he claims them to be.” When it comes to his full-color projections, Wallace gripes that Mayer’s mathematical distortions have made butterfly wing patterns impossible to identify. This warping, no matter how orderly, “renders the patterns of the most familiar species almost unrecognizable.” They amplify “what may be very slight differences” and obscure the “wonderful similarity” between mimicking butterflies.

Mayer’s projections, Wallace writes, “will seem to most naturalists to be a great mistake.” But we might read Color and Color-Patterns not just as the work of a cut-and-dry naturalist, but also as an ode to color itself: “color,” as his biographer notes, “even apart from form.” Plates five through eight stand out from an otherwise monotone tome, with vivid, almost psychedelic swirls of organic color. Each gridded abstraction is moody, atmospheric. In some, strange geometries emerge: gently curving swoops of yellow, rust-red blots, and graceful columns of orange and black. Others are more jagged and phrenetic, with fragmented puzzle pieces of white and yellow and blurring, feathered textures. Mayer’s butterfly wings seem to be an aesthetic indulgence that rises above the simply observational. They undulate, jump off the page, and call to mind the entomological romances Mayer gestured to, at the end of his life, as the kernel of his calling to the natural sciences.