Well, my little patch of beans has fed us faithfully through the season, we have included green beans in most meals for months. During the last flush of fruit I have left the beans on the plants to mature. This year I planted Pioneer and Barlotti bush beans, I have left the Barlotti pretty much to themselves because they are grown primarily for their seed, which is used in dishes like Baked beans, or included in soups and stews. I also find the pods tough and stringy. Now the plants have died down (mostly) and have dried pods hanging from them everywhere.
I went out and collected the first of many piles of dead pods with their secret stash of bean seeds inside. These were bought in and de-seeded while I listened to a podcast (pun intended). The resulting small pile of seeds where sorted into stained seeds (keep for next years planting) and good seed (keep for eating). I hope to gather a small jar full of seed this year and enough seed to plant a larger crop next year.
By collecting my own seed and growing it in my garden I help the plants to adapt to my conditions. Plants evolve much faster than animals (except insects), and those little traits that make a plant successful in your garden are passed on to the next generation. Every year the plants are more and more adapted to my particular soil, climate and gardening style. Every year those bean seeds become more entangled with me, until they are a little piece of me. That is why the passing on of a traditional seed type is so precious; the gardener is not just giving you seed, they are giving you a piece of themselves.