Aileen Bohan

Maybe some of you knew about those but it's the first time I've come across them and it blew my mind. So we're on a beach in the Philippines and we kept seeing these egg-like green balls in the seagrass. At first I thought they were plastic because they looked kind of like plastic toy capsules. But there were so many of them all over the beach that either some kid had lost the biggest toy collection in history, or something else was going on. So I checked and turns out they're called "Sailor's Eyeballs" (Valonia ventricosa) and each one is a single-celled organism, one of the largest on earth. Yup, that's one cell: the "plastic" shell is its cell wall, and everything inside is made of nuclei and cell sap. I never knew cells could get that big, I always assumed - wrongly, it turns out - that all cells were microscopic. You learn everyday!