Young European edible frog, Rana esculenta, undergoing the final stage of metamorphosis from tadpole to adult. Eggs are laid in early summer and hatch after about a week. After hatching the young tadpoles remain attached to the gelatinous egg envelopes while further development occurs; a membrane grows over the external gills, the eyes become functional, the mouth & anus break through and the tail elongates. The larvae finally develop into free-swimming tadpoles, which feed mainly on algae. Gradually the legs & lungs develop & the gills & tail degenerate until the tadpoles leave the water as fully-formed frogs.