At the turn of the century, mining was very productive in Northern California. Minig for gold, coal, silver and other types of precious metals and fossil fuels was what kept California alive. In order for miners to see what they were doing, they would take down with them gas burning lanterns. These men were often found digging hundreds of feet under the ground, with only the tunnel opening exiting back out into the open air above ground. These men often took a caged canary down with them during the entire time while they were digging away. Even though this little yellow bird is very pretty, it meant much more to these men than just a companion at these great underground depths. It is your job to thoroughly explain the physiological reasoning of why a canary was taken down. Justify all of your points and be very physiologically supportive of all that you state. Also, if you think that size has something to do with this, then why wasn't a mouse taken down instead?