So when is a frog a toad?

摘要

The name 'Polliwog', derived from the Middle English 'polwygle' and meaning 'head' (pol) plus 'to wiggle' (wiglen), is far more descriptive of a tadpole ('taddepol' - 'toad head') than the name we commonly use. Tadpoles, which can be seen along the edges of the canal in April, are most likely to be the larval stage of the common frog or the common toad, but how do you tell the difference? Frogspawn, which floats in large gelatinous clumps in shallow water, is usually laid earliest and the tadpoles, hatching after about three weeks, may be swimming as early as March.