The pollywog loses its tail

From one of the baby sites:

Your baby is somewhere between 1 and 1-1/2 inches in length and probably weighs about 4 grams (or as much as four paper clips). He or she has lips, toes, eyes that are usually open, ears that are completely formed, and the genitals are becoming more clearly defined. The little pollywog you have inside has lost its "tail" and this week marks the end of the embryonic stage and the beginning of the fetal stage!