Volvox (Volvox sp.) is a freshwater algae. Made up of many single-celled green algae, each one with a tiny pair of whip-like tails, they are linked together to form a hollow sphere. Inside this sphere you can see smaller daughter-colonies, which eventually come free when the original colony disintegrates. Volvox is more like a multicellular organism than a colony of single cells. It displays already the two essential features of a multicellular organism: the cells become specialized and they cooperate. Magnification: 30x.