A large horizontal watercolor of approximately thirty green creatures — the most chromatically unified of the specimen-sheet works, all forms rendered in variations of green from pale lime to deep emerald to yellow-green to gray-green. This is Sidney making an entire world from a single color, the variety within that color providing the compositional richness that other works achieve through chromatic range.
The creatures are the most specifically observed in any of the field works: each one is individually characterized with eyes, mouths, surface patterns, appendages. At lower left, a bright green lion-like form with a mane of fine marks — the most overtly animal form; at upper right, an elongated creature with blue stripes and a white ruff; at center left, a broad spotted creature with a red dot; at lower right, pale forms barely emerging from the white ground. No two are alike.
The variety within the green palette is the technical achievement: Sidney worked the full value range from near-white to near-black, all within the green family, allowing the forms to read distinctly without the aid of contrasting colors. This is a discipline — the same discipline that the black-ink East Asian works require, but applied to a full palette of one color.
The signed "S. Cothran" at lower left — unusually abbreviated — suggests this was completed quickly, in a sustained session, the signature added at the end of a long period of sustained drawing.