ZZ Plant Propagation

While I was moving around my monster sized zz plant and trying to get it in a better corner of the house and evening out the sunlight I knocked over a leaf or two. I stuck them in the pot with the begonia back in March. I heard they take forever to root but being curious and impatient, I dug one up today to check out its progress. And I found this!

ZZ Plan root bulb thing
A root bulb thing.