sentences:  Egg masses are laid either in single layers on the upper surface of leaves overhanging freshwater or in clusters connected to floating vegetation within the water itself, depending on various environmental factors.Hourglass tree frogs are unique in their reproductive plasticity, allowing them to produce both aquatic and arboreal eggs.Arboreal eggs are deposited on the upper surfaces of leaves overhanging water, so the tadpoles can roll into the water once hatched, and aquatic eggs are attached to floating vegetation within the water to keep the eggs from sinking.