Retinulae

Part of speech: noun

Definitions

1. A cluster of photoreceptor cells found in some invertebrate eyes that facilitate the detection of light
2. Structures composed of specialized cells that contribute to vision in certain organisms, particularly within compound eyes
3. An arrangement of sensory cells in the eye of certain animals, enabling them to perceive visual stimuli through light detection

Etymology: "Retinulae" is the plural of "retinula," a term for the light-sensitive cell cluster in insect and crustacean eyes. The singular was borrowed from New Latin "rētinula," a diminutive built on Medieval Latin "rētina," which is the root behind the English "retina." The "-ula" ending is the Latin diminutive suffix, so the word means something like "little net" or "little retina." The logic is a little tidy: a retinula is a small bundle of cells that works as a miniature version of the retina in a vertebrate eye, which is why the name borrows the larger structure's name and shrinks it. Medieval Latin "rētina" itself traces back to the Latin "rēte," meaning "net," which fits the image of fine interlaced fibres.