About this work
- The work is held at the **Smithsonian American Art Museum** (accession no. 1950.2.26B), gifted by the heirs of Abbott Handerson Thayer. - It is a **watercolor**, dated **late 19th–early 20th century**. - It depicts a caterpillar whose markings and form mimic the edge of a white birch leaf — a study in natural camouflage (leaf-edge mimicry). - It was made as a preparatory study for the book *Concealing Coloration in the Animal Kingdom*, published in **1909** (with Gerald H. Thayer listed as author/compiler, based on Abbott's discoveries). - The broader series of caterpillar studies in this project explored countershading and mimicry; the book was illustrated by Abbott, Gerald, Emma Beach Thayer, Richard S. Meryman, Rockwell Kent, and others. - Thayer considered this scientific work — which he called his "second child" — a direct extension of his artist's trained eye, arguing that perceiving camouflage was fundamentally an artistic act. - Thayer later lobbied Allied powers to adopt military camouflage based on these theories.
The elongated vertical format of this watercolor — 320 × 1,400 pixels in the Smithsonian's digitized version , suggesting a tall, narrow composition — tells you something immediately about its subject: a caterpillar rendered at close range against the serrated silhouette of a white birch leaf, the creature's body aligned with the leaf's edge as if it and the foliage are a single, continuous form. The palette is precisely keyed to its argument — pale greens, creamy whites, and the translucent ivory of birch tissue, with the caterpillar's markings dissolving into leaf veins and shadow in a way that makes the eye work to find the animal at all. This is scientific illustration as visual puzzle, and the watercolor medium is perfectly chosen: its washes of color can be layered to near-transparency, replicating the exact quality of light through a leaf that the caterpillar exploits.
The work dates to the late 19th to early 20th century and belongs to a major body of preparatory material assembled for what Thayer called his "second child" — the theoretical treatise on natural camouflage. Thayer's 1909 book *Concealing Coloration in the Animal Kingdom*, completed by his son Gerald H. Thayer, argued for the widespread use of crypsis among animals and in particular described and explained countershading for the first time.
The book was illustrated by Abbott H. Thayer, Gerald H. Thayer, Richard S. Meryman, and others including Emma B. Thayer and Rockwell Kent.
Thayer came to believe that this theory belonged to artists, with their trained perception: "The whole basis of picture making consists in contrasting against its background every object in the picture," he argued. The caterpillar studies, including this one, were among the most technically demanding illustrations in the project — requiring the painter
