Audible dot com is the leading provider of downloadable digital audio books and spoken word entertainment. Audible has over one thousand titles to choose from to be downloaded to your iPod or MP three player. Go to audible podcast dot com slash brain stuff to get a free audio book download of your choice when you sign up today. Welcome to brain Stuff from how stuff marks dot com where smart Happens. Hi Am Marshall Brain with today's question, how
does a chicken's egg get its shell? I mean, does the chicken make this shell and then fill it with an egg white and a yolk? Or does it make the egg white and the yolk and then wrap a shell around it or what? It turns out that the chicken has little to do with the formation of the eggs shell. The egg actually grows the shell around itself. It does this using a process that's also seen in
bones and seashells. Around the egg, there's a membrane, and on the membrane there are evenly spaced points where columns of calcite form. These columns stacked together side by side to form the shell. The calcium columns grow like crystals, and they fuse together to make a complete shell. The calcite is basically floating in solution around the shell. Once the membrane is put in place and it deposits on the membrane to form that crystal, the egg grows its
own shell. For more on this and thousands of other topics, is It How staff works dot Com? Streaming TV shows and movies directly to your home is a breeze with Netflix. As a Netflix member, you can instantly watch TV and movies on your PC, Mac, mobile device, or television. Get a free thirty day trial membership. Go to Netflix dot com, slash stuff and sign up today.