"A hybrid seed is like a mule. Mules are the offspring of a female horse and a male donkey. A mule is a naturally occurring animal, but it can't reproduce. Hybrid seeds are the same way. It's not like eating a hybrid will kill you; it just can't reproduce well. Usually the seed packet will say "hybrid" on the front, so you can tell savable seeds from non-savable."
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.