BALTIMORE — Until I met Doug Allen, the wiry, ponytailed senior aquarist who guided me through the extremely popular jellyfish exhibit at the National Aquarium, my personal experience with jellyfish consisted mainly of using them as yet another excuse not to go swimming: “Hey, I could get stung by a jellyfish!” Isn’t that what happened to 1,800 people off the coast of Florida last week? So when Mr. Allen suddenly stopped, clambered a ladder to the top of one of the tanks and called down, “You want to try holding a moon jelly?” my first impulse was to knock a few schoolchildren out of the way as I bolted for the door. My second impulse .. Read the full article