Harvesting Basil Seeds

I've had a basil plant out on the patio this season. It's been so nice to be able to step outside and pluck off basil leaves to use in spaghetti sauce and other things that I'm cooking. In California we have a pretty long growing season and the plant is just now starting to look pretty worn.

I went outside today to trim off some of the gangly branches and it occurred to me that I might look for some seeds. The picture of little dried out blossoms in the palm of my hand hold 4 seeds each.
I spent some time out in the sunny weather to extricate a number of seeds shown in the tiny dish.

My friend Barbara told me to put them into an envelope and then into the refrigerator where they will last for years. She said she's got seeds that are 20 years old that are still good.