I was moseying down a gravel path alongside a ravine, occasionally bumbling into the bushes and trees to peer around the foliage. Of course I was searching for mushrooms, but this walk was turning out to be disappointing. I wondered if tomorrow they would peek up from under earth in the very same spots that I had rummaged around. Perhaps what makes mushrooms so interesting and alluring is the mystery behind what triggers each one to burst up resolutely from the ground. And of course to make things complicated, each species of fungi has its own special environmental recipe that it needs.