Adult Rana catesbeiana breed in June and July in Kentucky. The newly hatched tadpoles grow and differentiate until October. Growth and differentiation resumes in early May with approximately 95% transforming into froglets in June through August, 12 to 14 months after the eggs were laid. The remaining 5% transform in less than 12 months. Arguments are presented from the data and a review of the literature to shwo that the larval life period is not two to three years, as is commonly accepted, but is approximately one year.