Trochilidae

The story

Nearly every plate in Kunstformen der Natur depicts invertebrates, protists, or plants — Haeckel's own research specialties — which makes this crowded, jewel-toned study of hummingbirds (Trochilidae) an outlier in the best way: a rainforest canopy dense with a dozen species shown mid-flight and at rest, iridescent throat feathers picked out in metallic color the lithographic process pushed to its limit. Haeckel included it precisely because hummingbirds made his underlying argument almost too easy — few living things display color and form as ostentatiously patterned as these birds, direct evidence, in his view, of nature's aesthetic order extending even to warm-blooded vertebrates. What to notice: a nest with two eggs tucked at lower left is the plate's only still moment amid constant motion — the ordinary domestic fact underneath all that iridescent display.