Stalactites and stalagmites? Oh, that's so yesterday. Seriously, it's nice to see other people interested in the same random thing, even if no one seems to know why there's a difference. Merriam-Webster tells me the words date back to New Latin in the 1660s or 1670s, and so they were probably coined for someone's science research...but my inclination to look wanes beyond that.
Which is a good thing, really, since I've been distracted by sketch comedy.