guard cells
"Guard cells are like trap doors in the epidermis. They control stomata, which open and shut like mouths"
"Specialized epidermal
cells called guard cells are like valves to a leaf They can open and close in response to weather, light, and moisture They regulate the passage of water, oxygen, and carbon dioxide"
"The guard cells are like little mouths, opening and closing according to how much sunlight there is and how much moisture is in the air"
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.