This is a vintage black and white illustration depicting the life cycle of a moth or butterfly. The image is labeled 'Plate 21' at the bottom. It shows several stages of the insect's development, arranged around a central stem. Here's a breakdown of the stages, numbered as they appear in the image: 1. A small, elongated, fuzzy form, likely an early larval stage. 2. A rounded, bulbous shape, possibly a pupa or chrysalis. 3. A more developed pupa, showing some segmentation. 4. A moth or butterfly emerging from its pupal case, wings partially unfurled. 5. A fully formed moth or butterfly with wings spread, showing intricate patterns and markings. The illustration is done in a detailed, scientific style, with careful attention to the anatomy of the insect at each stage. The background is dark, which emphasizes the white and gray tones of the insect and stem. The overall impression is one of a vintage scientific illustration, likely from a textbook or field guide.